-NRLF 


GIFT   OF 


DEMONSTRATION  OF  THE  FUNCTION  OF 

THE    NKTUOMOTOR   APPARATUS   IN 

EUPLOTES  BY  THE  METHOD 

OF  MICRODISSECTION 


A  THESIS  ACCEPTED  IN  PARTIAL  SATISFACTION  OF 
THE  REQUIREMENTS  FOR  THE  DEGREE  OF 

DOCTOR  OF  PHILOSOPHY 
AT  THE  UNIVERSITY  OF  CALIFORNIA 


BY 

CHARLES  VINCENT  TAYLOR 


DECEMBER,  1918 


UNIVERSITY    OF   CALIFORNIA    PUBLICATIONS 

IN 

ZOOLOGY 

Vol.  19,  No.  13,  pp.  403-470,  plates  29-33,  2  text  figures         October  23,  1920 


DEMONSTRATION   OF  THE   FUNCTION   OF 

THE   NEUROMOTOR  APPARATUS   IN 

EUPLOTES   BY  THE  METHOD 

OF  MICRODISSECTION 


BY 
CHARLES  V.  TAYLOR 


UNIVERSITY  OF  CALIFORNIA  PRESS 
BERKELEY 


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Vol.  17.  1.  Diagnosis  of  Seven  New  Mammals  from  East-Central  California,  by  Joseph 

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2.  A  New  Bat  of  the  Genus  Myotis  from  the  High  Sierra  Nevada  of  Cali- 
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Nos.  1  and  2  in  one  cover.    August,  1916 10 

:;.  8p>  •  :-pes  platyceplialus,  a  New  Alpine  Salamander  from  the  Yosemite 
National  Park,  California,  by  Charles  Lewis  Camp.  Pp.  11-14.  Septem- 
ber, 1916  05 

4.  A  New  Spermophile  from  the  San  Joaquin  Valley,  California,  with  Notes 

on  Ammospermophilus  nelsoni  nelsoni  Merriarn,  by  Walter  P.  Taylor.    Pp. 
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5.  Habits  and  Food  of  the  Roadrunner  in  California,  by  Harold  C.  Bryant 

Pp.  21-58,  plates  1-4,  2  figures  in  text.    October,  1916 35 

6.  Description  of  Bufo  canorus.  a  New  Toad  from  the  Yosemite  National  Park, 

by  Charles  Lewis  Camp.    Pp.  59-62,  4  figures  in  text.    November,  1916 05 

7.  The  Subspecies  of  Sceloponts  ovcidentalis.  with  Description  of  a  New  Form 

from   the   Sierra   Nevada   and   Systematic   Notes    on    Other    California 
Lizards,  by  Charles  Lewis  Camp.    Pp.  63-74.    December,  1916 _..      .10 

8.  Osteological  Relationships  of  Three   Species   of  Beavers,   by  F.   Harvey 

Holden.    Pp.  75-114,  plates  5-12,  18  text  figures.    March,  1917 40 

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Charles  Lewis  Camp.    Pp.  115-125,  3  text  figures.    February,  1917 10 

10.  A  Distributional  List  of  the  Amphibians  and  Reptiles  of  California,  by 
Joseph  Grinnell  and  Charles  Lewis  Camp.  Pp.  127-208,  14  figures  in  text. 
July  1917  *^ 


UNIVERSITY    OF    CALIFORNIA     PUBLICATIONS 

IN 

ZOOLOGY 

Vol.  19,  No.  13,  pp.  403-470,  plates  29-33,  2  text  figures        October  23,  1920 


DEMONSTRATION  OF  THE  FUNCTION  OF 

TIIK  NKU.'O.MOTOU  A  IM'A  U'ATTS  IN 

BUPLOTES   IJV  TIIK  MKTIIOI) 

OF  MI(M?()I)ISSK(TION 

BY 

CHARLES  V.  TAYLOR 


CONTENTS 

I'ACiE 

Introduction    

Acknowledgments  -.. 

Mi'tliod  anil  material 

Moist   chambers   

Binocular  microscope  

(llass  needles  

Control    

Staining   

Material  ••  417 

The  living  organism  418 

Endoplasm  *" 

Ectoplasm    ••  42° 

Macronueleus    

Micronucleus  

Contractile  vacuole  

Anal  aperture  

Cirri    

Membranelles    426 

Xeuromotor  apparatus   '-' 

Movements    428 

Experimental  

Pellicle   •  431 

Fibrillar  system  432 

Transections    435 

Excisions   -  439 

Incisions  441 

Discussion    444 

Summary    456 

Literature  cited   _ 458 

Explanation  of  plates 462 


;  ,,\, -\\Uiviversitij  of  California  Publications  in  Zoology       [VOL.  19 


INTRODUCTION 

Protozoa  are  commonly  regarded  as  representatives  of  the  most 
primitive  and  simplest  forms  of  life.  The  most  salient  feature  of  the 
phylum  is  conceded  to  be  their  unicellularity.  each  individual  being 
the  morphological  equivalent  of  a  single  cell.  That  these  characteristics 
indiscriminately  applied  to  this  very  large  and  diversified  group  of 
organisms  are  not  only  inadequate  but  somewhat  misleading  is  par- 
ticularly evident  from  several  recent  investigations  on  various  flagel- 
lates and  ciliates.  The  results  of  these  researches  point  toward  com- 
plexity rather  than  simplicity  and  stimulate  inquiry  into  the  nature 
and  function  of  certain  intracytoplasmic  structures  that  these  animals 
possess,  which  may  indicate  an  organization  more  highly  evolved  than 
is  usually  assumed. 

These  structures  in  both  flagellates  and  ciliates  are  intimately  asso- 
ciated with  ectoplasmic  organelles  (flagella,  cilia,  cirri,  etc.),  a  fact 
which  strongly  suggests  that  they  share  some  role  in  the  animal's 
motor  mechanism.  Accordingly,  investigators  are  generally  agreed  in 
designating  the  structures  with  their  attached  organelles  "the  motor 
apparatus. ' ' 

Of  the  organisms  possessing  such  a  motor  apparatus  a  larger 
number  of  flagellates  than  of  ciliates  has  been  studied  and  compara- 
tively described.  In  the  former  class  a  series  has  been  worked  out  that 
indicates  a  progressive  evolution  of  this  mechanism.  A  simple  type 
of  motor  apparatus  appears  in  the  biflagellate  stage  of  the  soil  amoeba, 
Xiiii/Jtrin  f/ruberi  (Schardinger).  It  consists  of  two  flagella  attached 
to  a  basal  corpuscle,  the  blepharoplast,  which  in  turn  is  connected  by 
a  fine  fibril  to  the  nucleus.  This  organism  spends  most  of  its  excysted 
life  as  an  amoeboid  trophozoite,  but  it  may  become  transformed  for  a 
brief  period  of  twenty-four  hours  or  less  into  a  very  active  flagellate. 
This  interesting  change  has  been  described  by  "Whitmore  (1911), 
Alrxeieff  (1912),  and  more  completely  by  Wilson  (1916),  who  has 
shown  that  variations  in  temperature,  media,  and  other  factors  may 
induce  the  change.  The  actual  transformation  may  be  followed  in 
living  forms  and  its  stages  analyzed  in  fixed  material. 

It  was  thus  observed  that  the  motor  apparatus  arises  by  an  out- 
growth from  the  karyosome.  "presumably  from  the  centriole,"  Wilson 


Tiiiilur:  Neuromotor  Apparatus  in  Ki/iilntix  405 


slates.  "which  crosses  the  clear  unclear  /.one.  emerges  through  the 
nuclear  membrane"  whence  arises  a  plastic  thread,  the  rhizoplast,  that 
emls  near  the  periphery  in  the  blcpliarnplast.  The  two  tlairdla  grow 
out  from  this  blepharoplast. 

The  origin  of  the  apparatus  from  the  centriole  is  not  clearly  estab- 
lished. This  centriole  can  be  seen  within  the  karyosome  during  the 
entire  development  of  the  liagclla.  although  its  division  may  give  rise 
to  these  structures.  Dr.  Swexy  (101(>)  offers  a  critical  discussion  of 
this  point. 

A  less  primitive  motor  apparatus  is  met  with  in  Prowazekia 
lai-<r/in  (Grassi),  a  parasitic  flagellate  found  within  the  intestine  of 
amphibians.  The  form  is  described  by  Alexcieff  (1912).  and  Janicki 
(1915).  and  its  motor  apparatus  critically  compared  with  that  of  other 
flagellates  by  Swexy  101(0.  One  stage  in  the  life-cycle  shows  a  motor 
mechanism  quite  similar  to  that  of  the  flagellated  soil  amoeba,  including 
two  flagella  attached  to  the  blepharoplast  which  is  connected  by  the 
rhizoplast  to  the  nucleus.  This  condition  becomes  modified  by  an 
enlarged  blepharoplast  that  elongates  and  buds  off  its  larger  portion 
to  form  the  parabasal  body.  The  latter  structure  remains  attached  to 
the  blepharoplast  by  a  rhizoplast  and  so  shares  a  part  in  an  integrated 
motor  apparatus  that  is  typical  for  several  other  forms  of  the  series. 
The  parabasal  body  is  described  in  some  protozoological  literature 
under  the  name  "kinetonucleus.  "  Protozoologista  using  this  nomen- 
clature designate  the  nucleus  "trophonucleus.  "  The  former  is  held 
to  be  a  product  of  the  hitter,  is  composed  of  nuclear  chromatin,  and 
divides  mitotieally.  But  more  recent  researches  do  not  substantiate 
these  claims  (Doflein,  1911,  Kofoid.  1015,  Swezy.  1016).  The  origin 
of  the  body,  as  in  ]'nnrn:i  kin  Ina  r/n<  ,  from  the  blepharoplast  to 
which  it  remains  attached,  is  a  fact  which  in  itself  establishes  the 
structure  as  a  component  of  the  motor  mechanism.  In  this  relation 
it  has  been  regarded  as  an  accessory  kinetic  reservoir  which  supplies 
oxidizable  material  to  the  locomotor  organelles  (Kofoid  and  Swexy, 
1915). 

In  Trypanoplasma  counri  i  Martin.  1013).  occurs  a  further  com- 
plexity in  the  motor  apparatus  with  the  attachment  of  a  trailing 
flagellum  to  the  body  by  a  fairly  well  developed  membrane.  It  is  also 
significant  that  the  parabasal  body  is  here  considerably  elongated, 
extending  from  near  the  blepharoplast  lateral  to  and  beyond  the 
nucleus.  These  variations  are  regarded  (Swexy.  101(i)  as  represent- 
ing a  step  in  the  evolutionary  series  toward  the  conditions  that  obtain 


406  University  of  California  Publications  in  Zoology       [VOL.  19 

in  certain  trichomonads.  Of  this  genus,  Trichomonas  augusta  (Kofoid 
and  Swezy,  1915)  possesses  a  motor  mechanism  to  whose  blepharoplast 
are  attached:  (1)  three  equal  anterior  flagella,  (2)  one  intracyto- 
plasmic  flagellum,  the  axostyle,  (3)  a  trailing  flagellum  attached 
laterally  along  the  margin  of  the  undulating  membrane,  and  (4)  an 
elongated,  chromatoidal  rod,  the  parabasal  body,  which  lies  along  the 
proximal  edge  of  the  undulating  membrane.  Recalling  the  occurrence 
of  a  trailing  flagellum  and  the  elongated  parabasal  body  in  Trypano- 
plasma  congri,  an  homology  between  these  and  structures  (3)  and  (4) 
in  Trichomonas  augnsta  appears  obvious. 

But  the  complexity  of  the  motor  apparatus  does  not  end  with  the 
trichomonads.  In  the  other  genus  of  the  Polymastigina,  the  Octo- 
mitidae,  appear  further  advances  in  the  series.  An  amphibian  para- 
site, Octomitus  dujardini  (Dobell.  1909)  claims  for  its  motor  mech- 
anism a  pair  each  of  blepharoplasts,  parabasal  bodies  and  axostyles, 
and  three  anterior  flagella  attached  to  each  blepharoplast.  Omitting 
the  undulating  membranes,  Octomitus  is  really  the  equivalent  of  two 
trichomonads.  This  duplex  condition  does,  in  fact,  become  complete 
in  Giardia  (Kofoid  and  Christiansen,  19156,  Boeck,  1917),  the  remark- 
able motor  mechanism  of  which  rivals  in  complexity  that  about  to  be 
described  for  certain  ciliates.  There  is  a  duplication  here  of  each 
structure  found  in  the  apparatus  of  Trichomonas.  But  with  the  con- 
nection of  the  two  blepharoplasts  by  a  commissure  and  with  a  chiasmal 
crossing  of  the  anterior  lateral  flagella,  two  organisms  become  inte- 
grated into  one  individual  (Kofoid  and  Christiansen,  19156). 

It  was  suggested  by  Professor  Kofoid  (Kofoid  and  Christiansen, 
19156)  that  this  integrating  fibrillar  complex  in  Giardia,  associated 
with  the  blepharoplasts,  parabasal  bodies  and  the  very  active  organelles 
of  locomotion,  was  neuromotor  in  function.  To  the  system  he  assigned 
the  name  "neuromotor  apparatus"  which  has  since  been  applied  to 
homologous  fibrillar  systems  in  other  flagellates  of  the  above  series. 

The  series  indicated  in  the  foregoing  examples  has  been  consider- 
ably amplified  by  a  number  of  other  flagellates  (Swezy,  1916)  which 
show  greater  or  less  complexity  in  their  motor  apparatus.  For  the 
ciliates,  however,  no  such  assemblage  has  yet  been  made,  although  this 
large  field  would  seem  only  to  await  further  investigation.  Numerous 
forms  of  this  class  have  long  been  known  to  possess  intracytoplasmic 
structures  associated  with  their  motor  organelles,  but  the  morphological 
relationship  of  these  structures  has  been  completely  worked  out  in 
only  two  organisms. 


1920]  'I'/ii/l/i/-:  Neuromotor  Apparatus  in  l''u/>l<>tix 

Sharp  i  1!M-1  '  was  the  tirst  to  succeed  in  tliis  endeavor.  Working 
upon  a  parasitic  ciliate.  l>ii>l<iilii<i'n,>i  '»ni<!nhnn.  common  in  the 
stomach  of  the  ox.  this  investigator  discovered  a  system  of  fibrils  con- 
necting all  the  niot.pi-  orjanellex  of  the  oral  region.  Owing  to  the 
shape,  position,  relations,  and  staining  properties  of  this  system.  Dr. 
Sharp  regarded  it  as  having  an  unusual  significance. 

The  organism  in  several  respects  is  one  of  the  most  complex  among 
all  known  Protozoa.  The  body,  which  resembles  "a  short,  plump 

banana,"  hears  all  the  organs  of  1 miotion  and  food-taking  at  the 

anterior  end.  This  region  is  more  or  less  flexible  and  decidedly  con- 
tractile, while  the  remaining  portion  of  the  body  is  rigid,  free  from 
appendages  and.  for  the  most  part,  firmly  supported  by  an  e.xoskeleton. 
At  the  anterior  extremity,  toward  the  ventral  side  of  the  body,  is 

located  tl ylostome.  This  is  an  elliptical  aperture  surrounded  by 

an  oval  disk  that  bears  on  its  inner  border  a  circlet  of  oral  cilia.  The 
cytostome  opens  directly  into  the  oesophagus,  a  short  tube  which  ends 
blindly  beside  the  anterior  end  of  the  macronucleus.  Around  the 
outer  border  of  the  oral  disk  appears  a  row  of  heavy  adoral  mem- 
bi-anelles  that  function  chiefly  in  locomotion.  Encircling  these  mem- 
branclles  are  an  inner  and  an  outer  adoral  lip  dorsal  to  which  lies  a 
prominent  operculnm.  The  latter  structure  is  continued  dorsally  into 
the  dorsal  disk  which  is  surrounded  by  the  dorsal  membranelles. 
These,  like  the  adoral  membranelles.  are  locomotor  organdies. 

The  relation  of  the  above  structures  has  been  very  briefly  stated 
only  to  facilitate  a  review  of  the  excellent  description  Dr.  Sharp  has 
given  of  the  complex  motor  apparatus  found  in  this  ciliate.  The 
constituent  parts  of  this  mechanism  embrace  (1)  a  motorium  lying 
deep  in  the  ectoplasm  beneath  the  operculum,  (2)  a  dorsal  motor 
strand,  (3)  a  ventral  motor  strand.  (4)  a  dorsal  lip  strand,  (5)  oper- 
cnlar  fibers.  ((>)  oesophageal  fibers,  and  (7)  a  circumoesophageal  ring. 
The  relation  of  these  parts  to  the  organelles  with  which  they  are  asso- 
ciated is  best  described  in  Dr.  Sharp's  own  words.  In  a  specimen 
stained  with  his  modification  of  Mallory's  connective  tissue  stain,  the 
so-called  motorium  was  first  observed  as  a  mass  "which  had  stained 
rather  intensely  and  showed  by  transmitted  light  the  same  bright  red 
color  which  was  noted  in  the  case  of  the  micronucleus.  Further  in- 
vestigation along  this  line  revealed  the  fact  that  not  only  was  this  mass 
constant  but  (1)  that  it  was  connected  dorsally,  by  means  of  a  delicate 
strand,  i.e.,  dorsal  motor  strand,  with  the  bases  of  the  dorsal  mem- 
branelles. also  a  branch  strand  ran  along  the  base  of  the  inner  dorsal 


408  I'nh'irxi/ij  af  C/ilijnniin  I'lililii-uli/mn  in  Zoology        [VOL.  1!) 

lip,  i.e.,  the  dorsal  lip  strand;  ('2)  that  a  fine  strand,  the  ventral  motor 
strand,  ran  from  it  to  the  bases  of  the  adoral  membranelles,  also  that 
a  branch  strand  left  this  ventral  motor  strand  and  passed  along  the 
base  of  the  inner  adoral  lip,  the  adoral  lip  strand,  and  that  many  well- 
defined  fibers  passed  from  it,  following  the  contour  of  the  operculum 
toward  the  right  to  become  lost  in  the  immediate  vicinity  of  the  base 
of  the  right  skeletal  structure.  These  are  the  opercular  fibers.  Most 
interesting  of  all,  however,  was  Hie  apparently  perfectly  definite  con- 
nection with  a  ring  of  the  substance  surrounding  the  oesophagus  at 
just  about  the  level  of  the  outer  adoral  furrow.  This  ring,  which  is 
designated  as  the  circunioesopliageal,  as  well  as  all  of  the  fibers 
described  as  leaving  the  motorium,  showed  in  all  regions  the  same 
bright  red  color.  Other  fibers  also  staining  bright  red  are  found  in  the 
oesophageal  walls.  These  are  found  in  the  oesophageal  walls.  These 
are  called  the  oesophageal  fibers,  but  thus  far  it  has  not  been  definitely 
decided  whether  they  take  their  origin  from  the  motorium  or  directly 
from  the  circumoesophageal  ring,  probably  the  latter,  however" 
(Sharp,  1914,  p.  83). 

Inasmuch  as  this  complex  system  of  motor  mass  and  strands  is 
intimately  associated  with  the  motor  organelles,  one  is  justified  here, 
as  in  the  case  of  the  flagellates,  in  regarding  these  structures  as  a  part 
of  the  animal's  motor  mechanism,  whatever  their  specific  role  may  be. 
But  just  what  is  their  specific  function?  Three  possibilities  were 
obvious:  (1)  this  intracytoplasmic  system  may  be  skeletal,  for  sup- 
port; (2)  it  may  be  muscular,  the  strands  representing  primitive  con- 
tractile fibrils;  or  (3)  these  strands  may  have  conductive  properties 
with  the  motorium  functioning  as  a  coordinating  center  for  impulses 
passing  over  the  primitive  neural  fibrils.  After  weighing  the  evidence 
which  his  investigations  had  disclosed,  Sharp  concluded  that  the  last 
hypothesis  was  in  nearest  agreement  with  the  facts. 

The  skeletal  hypothesis,  adopted  by  Braune  (1913)  for  a  similar 
system  found  in  Ophryoscolex  purkynjei  of  the  same  family  as  Diplo- 
dinium  ecaudatum,  was  believed  by  Sharp  to  be  insufficient  for  his 
species.  The  diminutive  size  of  the  "motor  mass,"  its  nonconformity 
in  shape  to  the  particular  region  of  its  location,  and  the  want  of 
attachment  of  the  several  strands  to  any  fixed  structures  were  con- 
ditions unfavorable  to  such  an  interpretation. 

Nor  did  it  seem  probable  that  the  mechanism  is  contractile  in 
function.  If  it  were  so,  it  should  appear  attached  to  fixed  structures, 
on  the  one  hand,  in  order  to  affect  movable  structures,  on  the  other. 


'1'iii/lnr:    .\i  iir/nii/iliir  Ai'/Kii-nh/x  in   Kni>l<>lis  40!) 


whirl)  is  lint  the  r;lsr.  Furthermore.  the  organelles  with  which  the 
strands  are  associated  arc  never  translated  in  "the  direction  of  the 
strands  leaving  the  motorinm.  hut  rather  in  a  direction  at  right  angles 
to  the  course  of  the  tihers.  thus  inilitat  ing  against  a  contractile  func- 
tion for  the  tihers"  (Sharp.  1!»14.  p.  81 

The  perfect  coordination  in  the  activity  of  mobile  parts,  all  of 
which  are  supplied  liy  strands  from  the  centrally  placed  inotoriuin. 
and  the  advantageous  location  of  the  system  to  function  "as  a  center 
nf  motor  coordination  in  an  animal  which  is  exceedingly  active,  exceed- 
ingly responsive  to  external  stimuli  and  one,  moreover,  which  exhibits 
a  high  decree  of  selective  feeding."  are  phenomena  which  could  In- 
most satisfactorily  explained  on  the  hypothesis  that  this  apparatus 
functions  as  a  primitive  type  of  nervous  system  whose  coordination 
is  i  fl'ected  through  the  central  motor  mass,  the  motorium.  Accord- 
ingly, Sharp  gave  to  this  system  the  name  "  neuromotor  apparatus." 

fii  a  fresh-water  ciliate.  K>ii>li>l<x  /m/i/ln,  a  fibrillar  system  rom- 
paralile  with  that  of  Diplodinium  <  rni/ilnl  11  in  has  recently  hern  worked 
out  and  descrihed  liy  Yocom  (1918).  Tt  is  noteworthy  that  these  two 
forms  are  of  different  orders  and  habitats  as  well,  the  latter  an  Oligo- 
trichan  parasite  common  in  the  stomach  of  ruminants,  while  the  former 
is  free-living  and  a  member  of  the  order  Ilypotricha.  The  presence  of 
these  homologous  systems  in  ciliates  so  varied  in  mode  of  life  and  kin- 
ship indicates  the  possible  widespread  occurrence  of  comparable 
systems  in  numerous  other  forms  of  this  exceedingly  interesting  and 
important  group  of  protozoans. 

Let  us  now  consider  the  nature  of  this  "neuromotor  apparatus"  in 
K  n  liln  /-\  /m/illii.  as  found  and  described  by  Dr.  Yocom.  1'ivfacing 
this  consideration,  if  will  be  convenient  to  offer  a  very  brief  account 
of  the  external  form  of  the  animal  and  the  relative  positions  of  its 
ectoplasmic  oi-Lranelles.  The  body  in  general  contour  roughly  resembles 
the  bowl  of  a  tablespoon,  the  convex  surface  of  which  represents  the 
dorsal  side  of  the  oriranism.  and  the  concave  surface  its  ventral  side. 
For  the  anterior  end.  to  complete  the  figure,  one  should  picture  a  mere 
stub  of  a  very  broad  handle  still  attached  and  well  rounded  to  suit  the 
contour  of  the  bowl.  The  stub  would  then  represent  the  oral  lip  of  the 
animal.  This  lip  forms  an  anterior  projection  of  the  dorsal  side  over 
a  wide  triangular  cytostome  at  whose  posterior  apex  is  the  pharynx 
situated  on  the  left  about  halfway  down  the  body.  A  series  of  mem- 
branelles  borders  the  dorso-posterior  margin  of  the  oral  lip  and  on  the 
left  turns  ventrad  to  continue  along  the  left  side  of  the  cytostome  into 


410  Vnil'i  rxilij  <>(  CitHI'iii-iiiil   I'l/liUni/ irni.f    ill    Zon/u//;/          (Vol.  19 

the  pharynx.  The  remaining  external  organdies  embrace  eighteen 
styliform  cirri.  Of  these,  four  are  caudal  and  fourteen  ventral  in 
position.  The  right  anterior  ventral  surface  bears  nine  cirri,  of  which 
six  are  termed  frontal  and  three  ventral  cirri.  The  remaining  five  of 
those  ventral  in  position,  known  as  anal  cirri,  are  the  largest  and 
longest  and  are  the  most  important.  These  have  their  origin  at  the 
ends  of  the  five  ventral  grooves  about  twenty-five  microns  from  the 
posterior  end,  and  extend  backward  beyond  the  caudal  margin  of  the 
body. 

All  the  cirri  were  observed  by  Yocom,  in  agreement  with  Maupas 
(1883)  and  Griffin  (1910),  to  be  composed  of  cilia  with  distinct  basal 
granules.  The  component  cilia  are  imbedded  in  a  dense  plate  of  ecto- 
plasm just  beneath  the  pellicle,  the  plate  serving  as  a  firm  support  for 
the  cirrus.  Now  from  the  basal  plate  of  each  anal  cirrus  there  extends 
a  fiber  toward  the  anterior  end.  These  fibers  were  first  seen  and 
figured  by  Maupas  (1883)  who  briefly  described  them  as  joining  the 
five  anal  cirri  and  extending  forward  to  converge  and  unite  into  a 
single  thread  which  disappeared  near  the  anterior  end  of  the  animal. 
In  1903  Prowazek  found  similar  fibers  in  Euplotes  liarpa  and  Griffin 
(1910)  described  such  fibers  for  E.  worc.esteri.  Yocom,  however,  was 
able  to  trace  the  fibers  in  E.  patella  farthe-  forward  to  where  they  join 
one  end  of  a  very  small  bilobed  body,  "the  motorium."  "It  was  first 
seen  as  a  dark  body  in  animals  stained  with  iron-alum  haematin,  lying 
close  to  the  right  anterior  corner  of  the  triangular  eytostome.  In 
specimens  which  are  well  destained  this  body  is  seen  to  be  composed  of 
very  fine  granules  closely  grouped  together,  but  if  too  dark  it  has  the 
appearance  of  an  almost  homogeneous  body.  "When  stained  with 
Mallory's  stain  the  motorium  becomes  bright  red  from  the  acid  fuchsin 
and  lacks  the  granular  appearance  characteristic  of  specimens  colored 
with  haematin.  Plate  14.  figure  5  (mot.)  shows  that  this  motor  mass 
does  not  have  a  smooth  contour,  but  rather  that  it  has  ragged  edges 
with  processes  extending  out  into  the  surrounding  ^ctoplasm"  (Yocom, 
1918,  p.  355).  The  motorium  is  about  eight  :  herons  long  and.  as 
figured,  about  one-fourth  as  wide  as  it  is  long.  Joining  its  left  end  are 
the  five  long  fibers  from  the  anal  cirri.  These  fibers  converge  and 
appear  to  unite  with  the  motorium  as  a  single  strand. 

From  the  right  end  of  the  motorium  another  fiber,  the  anterior 
cytostomal  fiber,  was  found  to  pass  anteriorly  and  to  the  left  along 
the  proximal  border  of  the  oral  lip  and  the  bases  of  the  membrane! Irs 
throughout  the  entire  series.  Within  the  oral  lip  was  observeci  a 


Tiii/lor:  Neuromotor  Apparatus  in  Eni>lnttx  411 

conspicuous  "lattice-work  structure"  whose  bases,  like  those  of  the 
iiieiiihraiiclles.  very  closely  approximate  the  cytostomal  fiber.  Thus  is 
formed  Yocom,  1918)  "an  unbroken  fibrillar  complex  between  the 
heavy  anal  cirri  which  are  used  chiefly  in  locomotion  and  the  inein- 
hrauelles  of  the  adoral  /one  which  function  as  organs  of  food  getting, 
organs  of  locomotion,  and  as  tactile  structures."  Several  finer  and 
shorter  fibers  pass  out  from  the  base  of  each  of  the  other  thirteen  cirri 
but  Yocom  found  no  indication  that  these  libers  connect  with  any  part 
of  the  complex  uniting  the  membrancllcs.  the  lattice-work  structure 
of  the  oral  lip,  and  the  anal  cirri. 

Tlu* anatomical  continuity  of  this  fibrillnr  system,  its  selective  stain- 
ing properties,  the  anterior,  free  position  of  the  motorium  and  the 
intimacy  of  its  several  branches  with  the  large,  vigorous  anal  cirri, 
with  the  peculiar  diffused  lattice- work  of  the  oral  lip  and  with  the  ever 
active  membranelles.  these  were  significant  features  which  strongly 
suggested  that  the  whole,  unique  arrangement  must  have  a  function 
more  highly  specialized  than  merely  that  of  support  or  even  one  of 
contractility.  Rather,  the  system  here,  as  the  one  in  Diplodin'nun 
iriimliih/i/i.  should  be  regarded  as  possessing  properties  of  conductivity 
functioning  to  coordinate  the  movements  of  the  organs  with  which  it 
is  associated.  It,  accordingly,  was  also  designated  "neuromotor 
apparatus." 

The  morphological  evidences  which  Yocom 's  researches  have  yielded 
lend  strong  support  to  this  "neuromotor"  hypothesis.  Yet.  however 
significant  may  be  the  foregoing  evidences  favoring  the  function  of 
conductivity  for  this  novel  apparatus  in  Euplotcs,  to  establish  this  or 
any  interpretation  of  organic  function,  methods  beyond  the  bounds  of 
morphological  inquiry  must  be  introduced.  In  this  endeavor,  the  in- 
vestigator enters  another  field  of  labor,  viz.,  that  of  experimental 
biology,  the  need  and  importance  of  which  has,  in  comparatively  recent 
years,  become  more  fully  recognized  among  biologists.  Phenomena 
studied  and  described  by  the  morphologists  are  of  primary  importance. 
A  comprehensive  i>  owledge  of  a  structure  and  its  relations  is  pre- 
requisite to  an  understanding  of  its  function.  But  functions  can  not 
be  ascertained  by  exploring  and  mapping  parts.  Experimental  means 
must  also  be  provided,  otherwise  further  progress  is  impeded  and  may 
even  be  rendered  impossible. 

In  view  of  this  and  because  of  the  important  significance  that 
attends  the  theory  of  the  presence  in  certain  Protozoa  of  structures 
which  are  neural  in  function,  it  was  thought  advisable  to  undertake 
the  task  of  which  this  paper  is  an  account. 


412  University  of  California  l'iilili<-iiiit>nx  in  Znnlni/tj       [VOL.  19 


During  the  winter  of  1916-17  when  Dr.  Yocom  had  found  and  was 
studying  the  fihrillar  system  in  Eitplotes  patella,  it  seemed  to  me  that 
the  experimental  method  of  microdissection  might  be  successfully 
employed  to  aid  in  determining  the  actual  function  of  this  system 
and  that  Yocom  's  excellent  morphological  studies  might  be  supple- 
mented by  experimental  evidence. 

The  value  and  necessity  of  experimentation  wa.s  duly  recognized  by 
Dr.  Yocom,  who  has  already  added  several  experiments  of  another 
sort  to  this  essential  phase  of  the  problem.  "In  studying  Euplotes 
patella"  (Yocom,  1918,  p.  363)  "that  have  been  treated  with  very 
weak  solutions  of  certain  ahemicals,  such  as  neutral  red.  methylene 
blue  and  especially  nicotine,  it  ha.s  been  noticed  that  the  anal  cirri  and 
cytostomal  membranellcs  are  the  last  to  cease  moving.  The  other 
cirri  become  quiet  but  the  membranelles  and  anal  cirri  have  been 
seen  to  move  even  after  the  cytoplasm  lias  begun  to  break  up.  Such 
phenomena  favor  very  strongly  the  idea  that  the  motorium  .serves  as 
a  coordinating  center  between  the  anal  cirri  and  the  cytostomal  mem- 
branelles. However,  other  observations  on  living  animals  give  even 
stronger  evidence  in  favor  of  the  neural  function.  It  has  also  been 
noted  in  specimens  subjected  to  a  very  weak  solution  of  nicotine  that 
the  frontal,  ventral  and  marginal  cirri  continue  moving  even  after  the 
animal  has  ceased  to  swim  about.  The  membranelles  also  move  but 
more  slowly  than  in  normal  animals.  Occasionally  one  or  more  of  the 
anal  cirri  may  be  seen  to  make  a  feeble  movement  not  sufficiently 
strong  to  cause  the  animal  to  move.  However,  as  the  animal  revives 
from  the  effects  of  the  narcotic  and  begins  to  swim  about  by  vigorous 
kicks  of  the  anal  cirri,  a  decided  increase,  in  the  rate  of  movement  of 
the  membranelles  may  be  noticed." 


ACKNOWLEDGMENTS 

This  experimental  investigation  has  been  made  under  the  very 
helpful  direction  of  Professor  Charles  A.  Kofoid,  whose  kindly  and 
stimulating  criticisms  have  contributed  much  to  any  merits  the  results 
may  possess. 

My  thanks  are  also  due  to  Professor  S.  S.  Maxwell  for  several 
valuable  suggestions  on  methods  and  useful  literature. 


Tdfilur:    .\iiiriiiiiiifnr  A  if/i/init  us  in   l^ii/i/nh  x  41H 


.MKTIIOD   AND  .MAT  KIM  A  I, 

Tin-  method  of  microdissection  has  been  greatly  improved  with  the 
use  ..!'  glass  needles  manipulated  in  a  three-movement  holder  intro- 
din-cd  several  years  ago  liy  Dr.  .M.  A.  I'.arher  and  later  extensively 
employed  In  Kite  and  ( 'hamb.  rs  (1!)1l_M.  Kite  1!M:!,/  and  &),  Cham- 
bers f1!H4.  1!)1.">.  1017«.  b.  and  1!I1S)  and  Seifri/  (1918).  Tlic 
technique  used  liy  these  investigators  makes  possible  the  dissection 
and  observation  of  ova.  spennato/.oa.  fresh  tissues  and  Protozoa  under 
the  highest  magnification  of  the  microscope.  A  detailed  description 
of  the  method  is  -riven  by  Barber  (10141  which  has  been  elaborated 
by  Chambers  i  1H1.~>.  101*>.  T  have  made  use  of  the  principal  features 
of  this  method  in  these  studies  on  Kit/iluto;  jiniillii, 

The  efficiency  of  the  liarber  instrument  is  indeed  remarkable.  Con- 
siderable experience  was  found  necessary  for  drawing  the  finer  and 
m"st  serviceable  needles,  but  their  manipulation  in  the  three-movement 
holder  is  a  comparatively  simple  matter.  One  learns  the  adjustment 
of  the  screws  controlling  the  needle  almost  as  readily  as  the  operation 
of  a  mechanical  sta-re.  After  some  practice  the  facility  with  which 
the  apparatus  may  be  manipulated  and  the  feats  thus  made  possible 
with  a  pi  ass  needle  arc  rather  surprising. 

Mnixl  i  Itimilii  rs. — Two  forms  of  moist  chambers  have  been  success- 
fully employed.  A  Mausch  and  Lomb  monocular  microscope  havin.-r  a 
rotary  staire  was  first  used.  For  this  sta<re  a  convenient  round  moist 
chamber  was  devised  as  follows:  The  base  of  a  heavy,  extremely 
shallow  petri  dish,  in  diameter  slightly  less  than  that  of  the  rotary 
stage,  was  fastened  upon  the  latter  by  means  of  two  brass  posts  20mm. 
long  sen-wed  into  the  clip  holes  of  the  stage.  The  upper  ends  of  these 
posts  firmly  supported  the  top  of  a  large  stender  dish,  this  top  or  roof 
having  a  diameter  eijiial  to  that  of  the  bottom  or  floor.  It  will  lie 
observed  that  both  roof  and  floor  were  thus  securely  fastened  to  the 
rotary  stage.  On  the  other  hand,  the  wall  of  the  moist  chamber,  made 
from  the  upper  portion  of  the  stender  dish  mentioned  above,  was 
solidly  attached  by  two  brass  arms  to  the  shank  of  the  microscope  and 
was  of  such  height  as  to  permit  free  movement  of  the  roof  and  floor. 
A  hole  throuirh  the  wall  on  the  right  allows  the  insertion  of  the  needle 
into  the  moist  chamber.  Also,  a  circular  hole  20  mm.  in  diameter 


414  1'iiirt  rxilii  of  California  1' uhlications  in  Zoology       [VOL.  19 

appears  in  the  center  of  both  the  roof  and  the  floor.  Inside  the  cham- 
ber around  the  lower  hole  was  sealed  a  glass  ring  which  completed  a 
shallow  enclosure  for  water  or  moist  cotton.  A  heavy  steel  shank  sup- 
ported the  Barber  holder.  The  shank  was  clamped  to  a  metal  base 
upon  which  the  microscope  also  was  fastened.  This  sort  of  moist 
chamber  on  a  rotary  stage  has  one  advantage  of  much  importance  for 
the  microdissection  of  Protozoa :  while  the  animal  is  being  held  by 
water-glass  surface  tension  it  may  be  rotated  and  so  cut  through  any 
part  at  any  desired  angle. 

The  other  moist  chamber,  constructed  on  a  plan  very  similar  to 
those  described  by  Barber  (1914)  and  Chambers  (1915,  1918),  was 
used  with  a  mechanical  stage  on  a  Bausch  and  Lomb  binocular  micro- 
scope. The  mechanical  stage  was  reversed  and  fitted  onto  the  left  side 
of  the  microscope  stage,  the  Barber  instrument  being  attached  to  the 
right  side.  The  combined  use  of  the  mechanical  stage  and  the  Barber 
holder  is  often  advantageous  and  sometimes  necessary.  This  arrange- 
ment just  stated,  which  allows  the  free  use  of  both  hands,  has  been 
found  very  convenient.  For  a  detailed  description  of  the  rectangular 
type  of  moist  chamber,  the  articles  of  Barber  (1914)  and  Chambers 
(1915,  1918)  may  be  consulted,  and  further  account  of  it  here  is  un- 
necessary. 

Binocular  microscope. — Most  of  these  experiments  have  been  per- 
formed with  the  aid  of  a  binocular  (Bausch  and  Lomb)  microscope. 
Especially  for  microdissection  purposes,  this  instrument  is  much 
superior  to  the  monocular  microscope.  To  observe  clearly  the  position 
and  adjustments  of  the  needle  in  the  vertical  dimension  was  found  to 
be  very  essential  in  several  experiments.  As  will  be  described  later, 
all  the  anal  cirri  were  successfully  removed  from  a  few  animals  without 
any  apparent  injury  to  the  body.  This,  it  seems,  would  have  been 
impossible  with  only  monocular  vision.  Furthermore,  the  general  con- 
tour of  the  organism,  the  relative  positions  and  movements  of  its 
organelles,  the  cyclosis  of  the  granules  of  the  endoplasm,  the  contrac- 
tions of  its  vacuole  and  its  forms  of  behavior  in  creeping  and  swimming 
are  much  more  satisfactorily  studied  under  the  binocular  microscope. 
The  use  of  both  eyes  soon  becomes  fully  as  desirable  in  microscopical 
as  it  is  in  unaided  vision. 

Glass  needles. — Much  of  one's  success  or  failure  in  microdissection 
can  be  attributed  to  the  quality,  shape  and  size  of  the  needles  employed. 
Soft  glass  needles  are  of  little  value  in  making  incisions,  but  because 
of  their  flexibility  they  may  be  used  to  hold  the  protozoan  without 


Till/lit/-:  Neuromotor  Apparatus  in  l-'ufilnhx  415 

undue  presv  ii  re  and  without  injury  in  order  to  study  the  movements 
of  organelles  and  cyclosis  phenomena.  Needles  inadi1  of  -lena  ^lass 
were  found  to  lit-  very  suitable  for  general  purposes  and  especially 
useful  in  performing  t  ranseetions  and  the  excision  of  parts.  But  even 
more  serviceable  were  the  needles  drawn  from  a  hard  quality  of  Pyrex 
and  glass  tubing.  A  s])ecial  mixture  of  this  glass  may  be  obtained 
from  the  Corning  Glass  Co.,  Corning.  N.  Y.  This  is  less  flexible  than 
the  .lena  glass  and  apparently  not  as  fragile.  For  making  narrow 
incisions  and  the  excision  of  organelles,  quartz  needles  are  quite 


L 


d 

Fig.  A.     Types  of  glass  needles  used  in  microdissection. 

superior  in  every  respect.  The  costliness  of  this  material  becomes 
neu'lifjrilile  if  the  needles  are  drawn  from  lulling  that  is  about  one  half 
the  diameter  of  a  pin.  then  sealed  with  "orange  stick"  in  a  handle 
made  of  ordinary  glass  tubing.  In  fact.  I  have  come  to  use  this 
method  also  in  making  needles  of  Jena  and  I'yrex  glass.  These  were 
drawn  in  a  very  small  alcohol  flame,  but  an  oxygen-gas  or  oxy-acetylene 
flame  is  necessary  for  making  quartz  needles.  The  finest  points  were 
obtained  by  completing  the  needle  not  in  but  quite  near  the  flame. 
Muscular  sense  is  more  dependable  than  eyesight  for  drawing  very 
fine  points,  some  of  which,  especially  those  of  quartz,  are  less  than  a 
micron  in  diameter.  The  shape  of  what  may  be  called  the  shank  of 
the  needle  was  found  to  be  of  considerable  importance.  The  figures 


416  University  of  California  l'nl>li<-<ilii>i/x  in  Zoology       [VOL.  19 

above  (p.  415)  illustrate  four  forms  of  shanks  which  were  found  most 
serviceable.  For  convenience  1  have  named  these:  a,  right  angled;  b, 
acute  angled;  c,  obtuse  angled,  and  tl,  V-shaped  shanks.  NYcdles  a 
and  b  have  been  used  for  probing  or  tearing  regions  or  dissecting  off 
parts;  needles  c  and  d  for  making  incisions  and,  particularly  <1,  for 
bisecting  the  organism,  making  wide  incisions  or  snipping  off  organ- 
elles.  The  V-shaped  shank  affords  more  flexibility,  which  may  be 
increased  by  lengthening  the  V. 

Control. — To  provide  for  the  control  of  the  organism  during  opera- 
tion, several  methods  were  tried.  Fine  fibers  of  silk  and  of  cotton, 
also  very  finely  ground  particles  of  glass  were  sealed  with  agar  to  the 
surface  of  the  cover-slip.  These  afford  helpful  means  of  holding  the 
animal  in  place  for  the  beginner  until  he  lias  learned  the  rather  diffi- 
cult but  by  far  the  most  satisfactory  method  of  control,  namely,  water- 
glass  surface  tension,  suggested  by  Kite  (1913,  p.  146).  I  have  used 
a  very  small  pipette  with  a  rubber  tube  attached  for  the  mouth  as  a 
means  of  transferring  the  animals  and  reducing  the  volume  of  the 
hanging  drop  to  afford  just  the  necessary  amount  of  surface  tension. 
This  amount  one  learns  only  after  considerable  practice.  Allowing 
slight  degrees  of  evaporation  also  facilitated  this  proper  adjustment. 
The  animal  must  -be  held  in  place  but  a  further  increase  in  surface 
tension  may  cause  it  to  disintegrate,  often  with  explosive  violence.  A 
perfectly  clean  surface  of  the  cover-slip  and  a  wide  hanging  drop, 
say  10  mm.  in  diameter,  aid  greatly  in  obtaining  proper  surface  ten- 
sion. Another  fairly  satisfactory  and  more  simple  method  of  control 
is  to  confine  the  protozoan  within  a  very  small  hanging  drop,  the 
surface  tension  of  which  with  the  glass  is  greatly  reduced  by  applying 
a  mere  trace  of  paraffin  or  some  other  harmless  oil. 

In  making  an  incision,  the  needle  was  applied  suddenly  and  rather 
firmly  by  means  of  the  up-and-down  movement  screw.  After  an 
interval  of  a  few  seconds,  this  screw  was  slowly  turned  back  and  forth, 
which  caused  a  seesaw  movement  of  the  needle-point.  With  proper 
care  and  if  the  needle  be  not  too  flexible,  a  surprisingly  clean  cut  may 
thus  be  .made  without  any  loss  of  endoplasm.  Chambers  (1917a)  has 
very  helpfully  suggested  the  use  of  a  needle  not  exceedingly  fine  and 
the  importance  of  slow  movement  and  sufficient  time  in  making  an 
incision.  Otherwise  a  loss  of  endoplasm  usually  results  and  this  may 
be  followed  by  rapid  and  complete  disintegration.  This  outflow  of 
endoplasm  may,  however,  be  regulated  to  advantage  by  applying  a 
V-shaped  needle  near  an  animal  in  which  a  careful  incision  has  been 


T<ii/li>r:    \i  iiriiiiii'lur  .\  i>i>nnit  HX   in    l-'ii jilutt  s  417 

made  and  which  is  held  near  the  eduv  of  ;i  wide  but  very  shallow 
hanging  drop.  Hy  slowly  turning  Ilie  screw  I'm-  the  up-and-down 
movement,  delicate  changes  in  the  decree  of  stress  of  the  surface  film 

are  thus  effected,  an  outflow  of  endoplasm  may  he  indu I  and  its  rate 

of  discharge  varied  more  or  less  at  will.  As  will  later  he  described, 
this  atl'urds  a  study  of  several  interesting  features  including  the  nature 
anil  extent  of  the  ectoplasm  and  of  the  pellicle. 

S/niiiiiii/. --Several  vital  stains  have  been  employed  with  varying 
success.  For  the  study  of  the  external  organdies,  a  .0001  per  cent 
solution  of  haematoxylin  gave  the  most  satisfying  results.  This  was  also 
useful  in  staining  the  fibrillar  system;  certain  new  features  of  this 
system,  in  fact,  were  first  seen  after  the  animals  had  been  subjected 
for  about  eighteen  hours  to  this  stain.  Tt  was  incidentally  discovered 
that  a  very  weak  solution  (.001 -.0001  per  cent)  of  tannic  acid,  after 
eight  to  ten  hours,  distinctly  sharpens  the  outline  of  the  fibrillar 
apparatus.  This  is  apparently  due  rather  to  its  effect  upon  the  cyto- 
plasm, affording  a  contrast  which  discloses  more  clearly  the  apparatus. 
Neutral  red  (Griibler).  new  methyleiie  blue  R  (C.  C.  Co.),  toluidin  blue 
(iriibler)  are  among  other  vital  dyes  which  enhanced  the  view  of  the 
system  of  fibers.  Usually  for  dissecting,  however,  the  anal  cirri  fibers 
and  not  infrequently  the  motorium  with  its  attached  fibers,  may  he 
seen  clearly  enough  under  oil  immersion  (2  mm.  Zeiss  apochromat), 
without  the  aid  of  intra  vitum  dyes. 

For  studying  specimens  fixed  and  stained  before  or  after  dissection, 
the  several  fixatives  and  stains  employed  by  Yocom  (1918,  p.  342)  were 
used  with  good  results.  The  method  of  picromercuric  fixation  followed 
with  Mallorv's  stain  or  with  iron-haematoxylin  was  especially  valuable 
for  the  study  of  the  fibers  before  and  after  they  were  cut.  Delafield's 
haematoxylin  stains  the  fibrillar  apparatus  even  more  distinctly.  There 
was  some  evidence  that  the  cut  fibers  do  not  stain  so  deeply  with  the 
iron-haematoxylin.  but  this  has  not.  as  yet.  been  definitely  ascertained. 
-Much  care  is  necessary  in  staining  single  specimens.  Fixatives  were 
applied,  usually  hot,  by  means  of  the  pipette  (above  referred  to)  under 
tlie  low  power  binocular.  The  specimen  was  then  transferred  to  a 
cover-slip  or  slide  which  had  been  treated  with  Meyers  albumen  fixa- 
tive. After  a  distinct  film  had  formed,  the  slide  was  passed  through 
the  alcohols  and  stains,  visually  without  detachment  and  loss  of  the 
specimen. 

Material. — The  fresh  water  ciliate.  Euplotcs  patella,  possesses  cer- 
tain morphological  features  that  make  it  an  unusually  choice  subject 


418  I' nil •< rxih/  of  California  Publications  in  Zoology       [Voi..  19 

for  microdissection  studies.  Plate  29,  fig.  1,  illustrates  several  struc- 
tures which  are  very  favorable  for  operative  work  on  the  neuromotor 
apparatus.  The  large  C-shaped  nucleus  permits  the  cutting  of  the  anal 
cirri  at  several  points  with  no  injury  to  the  nucleus.  Also,  the  cyto- 
stomal  fiber  may  be  cut  at  various  angles  and  the  motorium  destroyed 
likewise  without  injuring  the  nucleus.  The  stiff,  fairly  tough  pellicle 
which  envelops  the  body  ably  maintains  the  normal  form  after  an 
incision,  often  very  deep,  has  been  made.  The  remarkable  firmness  of 
this  structure  makes  possible  the  removal  of  cirri  with  no  apparent 
injury  to  the  body.  The  projection  of  the  oral  lip  and  of  several  cirri 
affords  successful  excision  of  these  parts,  and  the  definite  grouping  of 
the  frontal,  ventral,  anal,  and  marginal  cirri  permits  various  transee- 
tions  and  combinations  of  transections  and  excisions  that  have  proven 
to  be  exceedingly  useful  in  studying  the  functions  of  these  groups  of 
organelles  in  creeping  and  swimming  movements.  The  location  of  the 
single  micronucleus  at  the  anterior  end  of  the  body  is  especially  favor- 
able for  ascertaining  more  accurately  the  specific  role  of  this  interest- 
ing and  important  organ. 


THE  LIVING  ORGANISM 

Owing  to  the  invaluable  aid  of  water-glass  surface  tension  for  the 
control  of  Protozoa  in  a  hanging  drop,  it  is  now  possible  to  study 
active,  living  organisms  in  minute  detail  under  the  highest  magnifica- 
tion. With  a  properly  constructed  moist  chamber,  the  time  limit  for 
this  study  depends  rather  upon  the  endurance  of  the  observer.  A 
living  Euplotes  was  held  continuously  within  the  field  of  a  2  mm.  Zeiss 
apochromat  lens  for  more  than  two  hours,  at  the  end  of  which  time, 
when  a  drop  of  water  was  added,  the  animal  swam  slowly  about ; 
within  half  an  hour  its  movements  were  apparently  normal.  This 
allotment  of  time  is  ample  for  a  complete,  detailed  review  of  all  the 
structures  and  movements  of  the  organism  that  may  appear  within  the 
range  of  microscopical  vision.  By  properly  adjusted,  transmitted  light, 
the  binocular  microscope  with  an  apochromat  lens  affords  here  the  view 
of  a  living,  active  form  that  rivals  any  of  nature's  finest  displays.  The 
study  of  living  organisms  always  lends  increased  interest  and  adds  the 
essential  complement  to  our  knowledge  of  the  structures  and  relations 
disclosed  in  fixed  material. 


Timlin-:  Neuromotor  Apparatus  in  Ki<i>ln/is  410 


ENDOPLASM 

In  his  microdisaection  studies  on  living  ova  of  certain  marine 
invertebrates.  Chambers  il!tl7«>  finds  their  cytoplasm  to  consist  of 
"a  hyaline  fluid  matrix  in  which  arc  imhcddcd  granules  of  various 
sizes."  The  granules,  classified  into  microsomcs  and  macrosomcs. 
differ  considcralily  not  only  in  size  but  also  in  number,  shape,  solu- 
bility, refractive  indices  and  in  chemical  reactions.  Rapid  tearing  of 
the  internal  cytoplasm  with  the  needle  induced  in  that  region  the  dis- 
solution of  the  macrosomee  and  liquefaction  of  the  cytoplasm  in  which 
the  niicrosonics  exhibited  distinct  I'.rownian  movements.  Such  injuries 
sometimes  spread  throughout  the  entire  cell.  Also.  a.  rapid  dissolution 
of  the  macrosomes  occurred  'with  the  outflow  of  the  cytoplasm  into  the 
sea-water  "if  no  protective  membrane  intervened."  The  microsomes 
were  much  more  resistant  and  displayed  the  dancing  Brownian  move- 
ment for  a  considerable  time  after  the  complete  disappearance  of  the 
liquefied  cytoplasm.  A  protective  membrane  frequently  formed  around 
a  mechanically  injured,  disorgaiii/ed  area  within  the  cell  or  on  the 
surface  of  endoplasm  exuding  through  a  rupture  of  the  surface-film 
or  ectoplasm.  This  membrane  is  directly  comparable  with  the  ecto- 
plasm. Both  represent  a  colloidal  gel  enclosing  the  endoplasm  which 
usually  exists  in  the  sol  state  but  may  come  to  form  temporary  organs 
such  as  the  cell  asters  (Chambers.  1917ft)  by  a  reversal  of  the  sol  to 
the  gel  state. 

A  similar  consistency  of  cytoplasm  can  be  identified  in  Euplotes 
l»if<Uii.  Here,  however,  the  general  appearance  of  the  endoplasm  is 
considerably  modified  by  food  vacuoles  which  are  of  various  sizes  and 
sometimes  numerous.  But  with  high  magnification  and  well-regulated 
light,  hosts  of  small  granules,  comparable  with  Chamber's  microsomes, 
appear  throughout  the  entire  body.  Larger  granules  or  macrosomes  are 
less  conspicuous  and  have  been  observed  only  in  the  endoplasm.  Both 
the  large  and  small  granules  are  larger  than  the  macrosomes  and  micro- 
somes described  by  Chambers.  The  small  granules  are  fairly  constant 
in  size,  with  a  diameter  of  about  one  micron  or  more.  Here  and  there 
within  the  endoplasm  they  exhibit  Brownian  movement.  They  appear 
round  and  are  highly  refractive.  The  large  granules  vary  from  three 
to  five  microns  in  diameter,  are  usually  opaque  and  often  irregular  in 
shape.  They  have  not  been  identified  in  the  ectoplasm  and  never 
appear  within  the  cyclosis  currents  of  the  endoplasm.  Mechanical 


420  University  of  California  1'nhlications  in  Zoology       [VOL.  19 

injury  by  rapid  movements  of  the  needle-point  causes  their  disappear- 
ance in  that  region  of  the  body.  They  may  be  observed  for  a  time 
within  small  globules  of  the'  cndoplasm  which  have  flowed  out  along  the 
sides  of  the  needle  and  become  enveloped  with  a  "protective  mem- 
brane." But  if  the  outflow  of  the  endoplasm  is  sufficiently  rapid  and 
of  such  quantity  as  to  prevent  the  formation  of  a  membrane,  these 
large  granules  quickly  swell  and  burst  or  otherwise  disappear,  and 
the  hyaline,  liquefied  endoplasm  disappears  leaving  only  the  small 
granules,  which  may  remain  for  hours  constantly  in  Brownian  move- 
ment. In  one  instance  this  dancing  movement  of  the  granules  con- 
tinued throughout  part  of  an  afternoon  and  evening,  a  period  of 
about  six  hours. 


ECTOPLASM 

The  outflow  of  endoplasm  and  disintegration  of  the  organism  from 
incisions  made  abruptly  or  from  other  causes  is  generally  rapid  and 
sometimes  explosive.  To  prevent  this  sudden  disruption  and  regulate 
the  rate  of  outflow  of  endoplasm,  a  method  which  has  been  previously 
described  (p.  416)  was  used.  This  method  permits  a  careful  study  of 
the  ectoplasm  and  pellicle.  The  ectoplasm  consists  of  a  comparatively 
thin,  gel  matrix  with  densely  packed  small  granules  of  a  dimension 
similar  to  that  of  the  smaller  granules  of  the  endoplasm.  These  ecto- 
plasmic  granules  appear  equally  numerous  throughout,  closely  approxi- 
mating the  pellicle  on  one  side  and  the  endoplasm  on  the  other.  Griffin 
(1910ft)  describes  similar  granules  in  the  ectoplasm  of  E.  irorcestcri 
which,  however,  vary  in  size  and  appearance  more  than  do  these 
granules. 

Frequently,  there  is  evident  a  fairly  definite  boundary  between  the 
ecto-  and  endoplasm  but  this  condition  apparently  varies.  If  its  out- 
flow be  not  too  rapid,  the  endoplasm  separates  from  the  ectoplasm  and 
pellicle,  sometimes  leaving  large  areas  that  may  remain  intact  for 
several  seconds.  "With  further  disintegration  of  such  areas,  the  pellicle 
and  matrix  of  the  ectoplasm  quickly  disappear,  but  the  granules  here, 
like  the  ' '  microsomes ' '  of  the  endoplasm,  may  persist  for  several  hours 
in  continuous  Brownian  movement.  Plate  33,  fig.  23,  shows  a  .portion 
of  ectoplasm  with  a  frontal  cirrus  attached.  The  position  of  granules 
on  one  side  illustrates  the  manner  of  disintegration. 

A  further  discussion  of  the  pellicle  appears  under  the  caption 
"Experimental." 


Neuromot or  Apparatus  in 


42] 


MACRONUCIJ 

The  outline  anil  structure  tit'  tin-  large  ('-shaped  macroiiucleus 
appears  in  the  living,  unstained  organism  very  much  as  in  the  lixed 
material  figured  and  deserihed  liy  Yocom  (  HUSK  The  "contraction 
phase"  cil'  this  organ  with  its  reconstruction  bands  may  be  clearly 
observed  in  animals  free  from  too  many  food  vacuoles.  Hut  these 
features  and  partimlarly  the  granular,  mesh-work  consistency  of  the 
inaeronni-leus  can  be  much  more  satisfactorily  studied  after  the  latter 
has  been  dissected  out  with  the  needle.  It  is  then  found  to  be  a  highly 


rrt.p. 


mac. 


Fi'j.  H.     Tlio  nuclei  of  E>i/ilnlix.     ,-.< ..  cut  end:  <;/•„  crtoplasmic  granules;  mac., 
niiicronurleus;    HH'C..  micronucleus;   n.p.,  nci'illc   point. 


irelatinoiis.  rather  rigid  struoture  composed  of  small  granules  imbedded 
in  a  viscous,  hyaline  matrix  (text  fig.  B).  The  organ  is  enveloped  by 
a  very  thin,  structureless  membrane.  1'pon  exposure  to  the  water,  the 
macronudeus  increases  slowly  in  size;  within  hall'  an  hour  or  so  small 
blisters  of  the  membrane  slowly  appear  over  the  surface;  the  rate  and 
extent  of  swelling  increases  and.  upon  rupture  of  the  membrane  in  one 
or  several  places,  there  follows  a  rapid  dissolution  of  all  except  the 
small  granules,  which  for  several  hours  exhibit  a  dancing  Hrownian 
movement.  These  granules  vary  somewhat  in  size,  with  an  average 
diameter  about  one  fourth  that  of  the  microsomes  found  in  the 
endoplasm. 


422  Unirtrsili/  of  ('nlifuniin  I'lili/ii-nHmiM  in  Z</</It,(/i/        [VOL.  19 


MlCEONUCLEUS 

This  organelle  is  much  less  conspicuous  than  other  organs  in  living, 
unstained  animals,  but  when  once  clearly  identified  it  may  always  he 
readily  located  with  suitable  magnification  and  properly  regulated 
light.  The  variations  in  position  and  size  depending  upon  its  several 
pliaxes  (Yocom,  1918)  have  been  defintiely  verified  even  without  the 
aid  of  vital  dyes.  With  a  .0001  per  cent  aqueous  solution  of  neutral 
red,  haematoxylin,  methylene  blue  or  Bismarck  brown,  both  micro- 
and  macronueleus  become  sharply  outlined  and  the  visibility  of  their 
structure  is  considerably  enhanced.  Several  times  the  macronucleus 
has  been  dissected  out  with  the  micronucleus  attached  and  lying  in  a 
very  shallow  pocket  (Griffin,  1910;' Yocom,  1918).  In  two  cases,  the 
micronucleus  was  brushed  with  the  needle-point  out  of  the  depression 
in  which  it  was  feebly  held  evidently  by  a  viscous,  ductile  substance 
that  stretched  only  for  a  few  microns  in  fine,  retractile  threads.  These 
properties  of  this  substance  indicate  that  it  may  be  comparable  with 
the  hyaline,  gelatinous  matrix  of  the  macronuclens.  Other  interesting 
features  of  the  micro-  and  macronucleus  will  be  treated  in  a  later 
paper. 

CONTRACTILE  VACUOLE 

My  observations  on  the  size  and  position  of  this  organelle  are  in 
general  agreement  with  Yocom 's  (1918).  although  I  have  observed  an 
abnormal  increase  in  its  size  after  certain  vital  stains  such  as  neutral 
red,  Bismarck  brown,  Congo  red,  gentian  violet,  fuchsin  S.  etc..  have 
been  added  to  the  water.  Moreover,  any  distinct  mechanical  disturb- 
ance, e.g.,  rapid  movement  of  the  needle  to  and  fro  through  the  hang- 
ing drop,  continually  jarring  or  shaking  the  moist  chamber,  etc.. 
effects  very  noticeable  changes  in  the  size  and  period  of  pulsation  of 
the  vacuole.  One  should  then  expect,  as  is  the  case,  that  incisions, 
transections,  or  excisions  would  similarly  affect  this  organelle.  It 
would  appear,  indeed,  that  the  contractile  vacuole  in  Evplotcs  patella 
is  exceedingly  sensitive  to  various  stimuli.  The  average  size  of  this 
vacuole  in  ten  carefully  handled  animals  was  29  microns  at  maximum 
diastole.  Its  diameter  upon  disturbance  or  after  incisions  may  become 
45  or  even  50  microns,  and  its  period  of  pulsation,  which  is  normally 
about  forty  seconds  between  systoles,  may  thereupon  vary  from  three 
to  fifteen  minutes. 


Tmilnr:  Neuromot  or  Apparatus  in  Eiti>l»/is  4i':! 


The  discharge  of  the  vaciiole  is  clearly  on  the  ventral  side  within 
three  or  four  microns  of  the  right  margin  of  the  pellicle.  This  may  he 
observed  with  careful  focusing  when  small  food  vacimles  are  lying  just 
posterior  to  the  point  of  discharge.  The  relative  position  of  the  last 
trace  of  a  systole,  as  compared  with  that  of  the  food  particles  and 
ventral  pellicle,  appears  distinctly  ventral.  Also,  this  position  may  he 
verified  by  applying  the  needle-point  very  lightly  against  the  ventral 
surface  near  the  point  of  discharge,  whereupon  the  position  of  the 
discharge  is  ventral. 

ANAL  A  PERT  IT  BE 

.  This  has  heen  located  in  E.  ixitflla  on  the  ventral  side  slightly 
posterior  to  the  discharge  pore  of  the  contractile  vaciiole  and  within 
five  microns  of  the  margin  of  the  pellicle.  It  was  first  observed  when 
two  i'rustules  of  \<irirn/<i  were  seen  to  pass  successively  from  an  animal 
held  in  a  shallow  hanging  drop.  The  emission  of  various  other  feral 
particles,  mostly  very  .small,  has  since  been  noted  in  several  individuals. 
Voiding  apparently  seldom  occurs  when  the  stress  of  surface  tension 
or  the  pressure  of  an  applied  needle  is  increased.  In  only  three  cases 
lias  the  emission  of  particles  thus  been  observed.  However,  pressure 
from  the  needle  or  from  surface  tension  may  sometimes  cause  the  pro- 
trusion of  a  small  area  including  the  anal  pore.  Griffin  (IfllOa) 
describes  the  location  of  an  anal  opening  in  E.  u'orccsteri  immediately 
to  the  right  of  the  outermost  anal  cirrus.  This  closely  approximates 
the  position  of  the  pore  in  E.  patella.  But  the  pore  in  E.  u-orcestcri 
is  anterior  to  the  contractile  vacuole,  whereas  in  E.  patella  it  is  pos- 
terior. .It  should  be  said,  however,  that  the  position  of  the  contractile 
vacuole  varies  considerably  in  different  E.  patella  which,  of  course. 
somewhat  alters  the  relations  above  referred  to. 

CIHRI 

The  eighteen  styliform  cirri  of  Euplotes  patella  appear  on  the 
ventral  side  in  four  fairly  well  defined  groups.  Yocom  (1918)  classifies 
these  into  six  frontal  cirri,  three  ventral  cirri,  five  anal  and  four 
marginal  cirri,  which  is  in  agreemnt  with  Stein  (1859).  While  the 
groups  of  frontal  and  ventral  cirri  are  less  clearly  defined  than  are 
the  others,  it  is  at  least  more  convenient  and,  I  believe,  more  accurate 
to  regard  the  frontal  group  as  composed  of  seven,  and  the  ventral 
group  of  two  cirri.  Also,  for  further  convenience  in  describing  the 


424  Unir<  i-fiiln  of  ('(ilifnrnia  riil>/i<<//i»ns  m  /n»li></>j       |\"oi,.  i'.» 

mierodissection  experiments,  I  should  subdivide  the  seven  frontiil  cirri 
into  an  anterior  group  of  three  and  a  more  posterior  group  °'  t'our. 
Accordingly,  these  will  liereinafter  be  referred  to  as  the  "group  of 
three"  and  the  "group  of  four"  frontal  cirri. 

The  ciliary  composition  of  the  cirri  of  various  Kiipltihs  is  a  well 
established  fact.  The  component  cilia  with  their  basal  granules  have 
been  described  for  the  cirri  of  E.  nnnnix  by  .Minkiewiez  (1901}.  of 
E.  Jiarpa  by  Prowazek  (1902),  of  E.  worcegteri  by  (Jriffin  (1910).  and 
of  E.  patella  by  Yocom  (1918).  This  feature  of  a  cirrus  may  be 
readily  demonstrated  in  a  shallow  hanging  drop  by  means  of  a  V- 
shaped  dissection  needle.  Here  a  del  ached  cirrus  may  be  pushed  to 
the  edge  of  the  hanging  drop  for  greater  surface  tension  and  gently 
rolled  to  and  fro  between  the  needle  and  cover-slip.  Soon  the  cirrus 
splits  into  loose  bundles  of  its  numerous  cilia.  But  this  method  reveals 
other  features:  the  cilia  are  embedded  in  a  gelatinous  matrix  that  is 
highly  viscous,  as  may  be  seen  by  pushing  the  bundles  about  with  the 
needle.  These  remain  attached  at  one  or  several  places  even  after 
rather  rough  handling.  They  frequently  adhere  to  the  needle  and  so 
may  be  pulled  a  considerable  distance  through  the  water.  Upon  ex- 
posure to  the  water  for  a  few  minutes,  the  cilia  of  the  bundles  further 
separate  and  show  adhering  to  their  sides  minute  globules  of  the 
coagulated  matrix.  The  question  here  arises  whether  this  coagulation 
of  the  viscous,  hyaline  matrix  may  not  account  for  the  extreme  rigidity 
that  overtakes  the  cirrus  soon  after  its  detachment,  when  it  may  be 
pushed  about  and  even  beyond  the  margin  of  the  shallow  hanging 
drop  without  any  apparent  bending.  Furthermore,  after  examining 
numbers  of  these  cirri  by  the  above  method,  one  becomes  rather  con- 
vinced that  the  matrix-eilia  complex  is  invested  with  an  extremely 
thin,  structureless  membrane  that  is  fairly  tough  but  very  flexible.  I 
have  not  been  fully  satisfied  about  this  structure  since  I  have  not 
clearly  seen  it  apart  from  its  enclosure.  This  final  evidence  may  later 
appear.  However,  if  present,  the  membrane  rapidly  dissolves  from  a 
recently  detached  cirrus,  which  then  splits  into  its  component  cilia. 

Except  the  anal  cirri,  all  are  round  at  their  base  and  gently  taper 
to  a  rather  sharp  point.  The  two  right  marginal  cirri  are  fimbriated 
(Yocom,  1918).  Not  infrequently  the  second  and  third  (numbering 
from  left  to  right)  anal  cirri  are  also  fiinbriated.  The  shape  of  the 
base  of  the  anal  cirri  differs  considerably  from  the  others.  Figures 
19  and  18  show  the  comparative  dorso-ventral  width  and  lateral  thick- 
ness of  an  anal  cirrus  base,  the  former  being  six  to  eight  microns  and 
the  latter  about  three  microns. 


Tui/lnr:    \<  in-i'iiiiit'ir  .\i>inu-<ihin  in   /•.'///*/-//,  *•  4l'."> 

The  jitt;icliinciit  ill'  the  cirri  will  he  discussed  in  connection  with  a 
description  of  the  nclinunotor  ;i|)|>a  fill  us.  It  remains  here  to  describe 
lirielly  tlie  several  movements  that  are  common  to  the  different  groups 
of  cirri.  I'iitter  i  1!iu:!i  discusses  these  general  types  of  ciliary  move- 
ments aiming  I'roto/oa:  (1)  tlie  "hook-like"  type.  found  in  cilia  or 
tlagella  used  for  food-taking:  ( 1' i  the  "whip-like"  type,  exemplified 
I'.v  the  tlagellum  of  Kiii/hita.  and  3)  the  "  int'undihular  or  funnel- 
like"  type,  very  common  among  most  flagellates  and  ciliates.  The  anal 
cirri  of  H.  /nitiHii  frequently  exemplify  types  hot  h  I  i  and  2),  while 
t\  pes  1' i  and  (3)  are  common  for  their  frontal,  ventral,  and  marginal 
cirri.  Yoeom'a  observation  1M1S.  p.  :!(i:5i.  that  the  anal  cirri  "move 
in  only  one  plane,  that  parallel  to  the  median  plane  of  the  body."  is 
hardly  adequate.  As  will  he  described  presently,  these  cirri  arc  very 
frequently  used  in  guiding  tlie  animal  to  the  right  or  left,  and  are 

'  s| ially   active  as  the  chief  means  for  making  sharp  turns  to  the 

right,  which  is  not  an  uncommon  reaction  during  swimming.  In  the 
latter  instance,  part  ieularly  cirri  .'!.  4.  and  .">  (  numbering  from  left  to 
righO  are  flexed  rather  abruptly  near  their  base  and  lash  close  along 
the  ventral  surface  of  the  body.  (iritTin  C1910.  p.  :!(•!)  regarded  the 
anal  cirri  of  K.  Worcester*  to  have  "only  a  single,  strong  motion:  a 
vigorous  kick  directed  backwards. "  Tn  K.  jinhUn,  however,  this  back- 
ward stroke  is  by  no  means  the  only  effective  movement,  nor  even  the 
most  important.  The  "avoiding  reaction"  of  this  species,  which  will 
be  described  further  on.  is  effected  chiefly  by  means  of  the  anal  cirri. 
Furthermore,  these  cirri,  together  with  the  frontal  and  ventral  groups, 
are  the  animal's  "feet"  for  creeping  and.  as  we  shall  see  later,  upon 
removing  the  anal  cirri,  creeping  becomes  impossible. 

Another  common  use  of  these  anal  cirri  may  be  observed  in  their 
attachment  to  suspended  debris  in  the  water  and  swimming  about  with 
it  sometimes  for  several  minutes;  or.  less  frei|uently,  in  holding  on  to 
floating  debris  or  even  to  the  dissecting  needle  and  suspending  the  bodv 
dorsal  side  down,  occasionally  at  an  angle  of  fifteen  degrees  or  more. 
The  attachment,  to  the  needle  at  least,  is  usually  with  two  or  three  ami 
often  four  anal  cirri.  Tn  such  cases  I  have  observed  clearly  a  slight 
flexure  of  the  tip  of  one  or  more  cirri  about  the  needle  and  had  con- 
cluded this  to  be  the  means  of  supporting  the  body;  but  later,  an 
attachment  by  only  one  cirrus  was  seen  with  the  tip  several  microns 
in  length  lying  along  the  under  side  of  the  needle.  This  latter  obser- 
vation has  since  been  made  a  number  of  times  and  in  two  instances  I 
was  able  to  move  the  needle  slowly  back  and  forth  without  disturbing 


426  University  of  California  Publications  in  Zoology       [VOL.  19 

the  animal,  when  the  support  was  sufficient  to  carry  the  body  along 
with  the  needle.  As  to  how  this  curious  feat  may  be  accomplished  I 
can  only  conjecture  the  possibility  of  a  secretion  present  on  the  cirrus. 


MEMBRANELLES 

Projecting  anteriorly  from  along  the  dorsal  base  of  the  oral  lip,  the 
series  of  membranelles  turn  ventrad  on  the  left  in  a  gracefully  twisting 
curve  and  continue  along  the  left  side  of  the  cytostome  and  pharynx 
to  end  in  a  hooklike  turn  at  the  apex  of  the  pharynx.  Yocom  (1918, 
p.  4)  has  aptly  likened  the  twisting  and  general  shape  of  this  con- 
tinuous series  to  the  collar  and  lapel  of  a  coat.  His  splendid  detailed 
description  may  be  referred  to  for  the  more  minute  structure  of  these 
organelles.  A  further  description  concerning  only  their  attachment 
and  their  relation  to  the  neuromotor  apparatus  will  be  given  later 
under  the  heading  "Experimental."  However,  the  considerable  dis- 
cussion on  the  actual  relations  of  the  cilia  which  compose  the  mem- 
brancllcs  described  for  various  Euplotcs  is  here  worthy  of  note. 
Obviously,  these  relations  condition  the  shape  of  the  membranelles. 
For  E.  harpa,  Wallengren  (1901)  describes  and  figures  the  mem- 
branelles as  triangular  in  shape.  Minkiewiez  (1901)  found  those  of 
E.  vannws  to  be  of  a  similar  shape.  Yocom 's  discussion  of  this  point 
would  seem  to  favor  the  view  of  the  above  authors,  although  he  does 
not  refer  to  the  particular  shape  of  a  membranelle.  Griffin  (1910a), 
on  the  other  hand,  states  that  after  repeated  examination  of  these 
structures  in  E.  worccsteri,  he  is  inclined  to  believe  that  the  mem- 
branelles which  are  nearly  rectangular  in  shape  are  composed  of  dis- 
tinct cilia  ' '  with  movements  so  perfectly  coordinated  that  they  act  and 
ordinarily  appear  as  a  single  and  delicate  band"  (p.  299).  Mobius 
(1887)  had  come  to  the  same  conclusions  regarding  both  the  shape  and 
structure  of  the  membranelles  of  E.  harpa. 

Prom  the  present  studies  on  E.  patella,  I  am  convinced  that  the 
cilia  composing  a  membranelle  in  this  species  are  definitely  fused  and 
that  they  are  so  arranged  as  to  give  each  membranelle  the  shape  of  an 
elongated  triangle.  Indeed,  those  extending  over  the  oral  lip  (fig.  16) 
approximate  the  form  of  a  short  cirrus  with  a  very  wide  base.  By 
means  of  a  dissecting  needle,  several  of  those  dorsal  to  the  oral  lip 
may  be  excised,  together  with  a  portion  of  that  organ  from  which  they 
readily  separate,  and  thus  the  features  mentioned  above  may  be 
exhibited.  They  may  very  soon  split  into  bundles  of  component  cilia 


Tiitilnr:   Neuromotor  Apparatus  in  /•.'»/>/«/<.  <  427 


that  show  basal  granules  distinctly,  while  later  there  appear  along  the 
cilia  minute,  coagulated  globules  comparable  witli  thus.'  described  for 
the  cirri.  Also,  excellent  views  of  the  shape  and  arrangement  of  the 
entire  series  of  membranclles  may  be  had  upon  transferring  an 
organism  to  a  hantrintr  drop  of  0.1  per  cent  solution  of  tannie  acid.  The 
animal  usually  dies  within  a  few  minutes  but  in  the  meantime  the 
inembranelles  become  stained  and  their  movements  are  slowed  so  as 
to  afford  a  splendid  study  of  each  membranelle  of  the  entire  series. 

The  primary  function  of  the  mcmbranclles  of  the  cytostomal  and 
pharyngeal  region  is  food-taking.  Yoeom  (1918)  has  discussed  the 
manner  of  the  intake  of  food,  but  he  does  not  refer  to  the  expulsion 
of  particles  from  the  pharynx  after  they  have  been  "sampled"  and 
refused.  This  ejection  may  be  sometimes  rather  violent  and  is  effected 
by  a  reversal  of  the  membranelles  which  may  involve  only  those  of 
the  pharynx,  or  also  the  cytostomal  nu  mbranelles.  or  occasionally 
even  the  entire  series.  The  chief  function  of  the  adoral  membranelles 
is  their  indispensable  service  in  swimming:.  An  acount  of  this  im- 
portant feature  is  given  in  later  paragraphs. 

XKCROMOTOR  APPAKATI-S 

The  system  of  fibers  connecting  the  series  of  membranelles.  the 
lattice-work  structure  of  the  oral  lip  and  the  five  anal  cirri  to  a  small 
bilobed  body  lying  in  the  extreme  anterior  right  of  the  animal,  together 
with  other  fibers  radiating  from  the  base  of  the  remaining  thirteen 
cirri  were  found  and  described  by  Yocom  (1918)  as  the  neuromotor 
apparatus  of  Euplnti  s  patella.  In  preceding  paragraphs  I  have  given  a 
brief  but  fairly  complete  review  of  Dr.  Yocom's  account  of  this  appa- 
ratus. It  is  my  purpose  here  to  reconsider  certain  parts  of  his  account 
and  in  following  paragraphs  (see  "Experimental")  offer  a  few  minor 
modifications  and  additions  (fig.  13). 

Following  Yocom's  figures  and  descriptions,  I  have  been  able  to 
identify  in  the  living  organism  all  the  structures  of  this  interesting 
and  complex  mechanism.  The  anal  cirri  fibers  are  usually  distinctly 
visible  throughout  most  of  their  length.  The  presence  of  food  vacuoles 
dorsal  to  the  frontal  cirri  frequently  interferes  with  the  tracing  of 
these  fibers  to  their  junction  with  the  motorium,  but  this  interference 
may  be  obviated  by  keeping  the  animals  in  well-filtered  water  for 
several  hours,  at  the  end  of  which  time  most  of  the  food  vacuoles  will 
have  disappeared.  It  is  then  possible  to  observe  not  only  all  five  fibers 


428  I' nii'frxili/  of  California  1'ti/ilications  in  Zoology       [ VOL.  19 

throughout  their  extent  but  also  the  motorium  and  from  its  outer  end 
the  membranelle  fiber  passing  to  the  oral  lip  and  membranelles.  After 
they  are  once  clearly  identified  with  the  aid  of  vital  dyes,  the  motorium 
and  its  connecting  fibers  may  be  recognized  usually  with  little  difficulty 
in  unstained  animals. 

The  several  fibers  associated  with  the  base  of  the  frontal,  ventral, 
and  marginal  cirri  are  much  less  distinctly  visible.  Very  careful 
focussing  and  regulation  of  light  are  necessary,  and  even  then  it  is 
usually  impossible  to  make  sure  of  these  fibers  without  the  aid  of  vital 
dyes.  This  may  be  said  also  of  the  membranelle  fiber  along  the  base 
of  the  membranelles.  Here  the  presence  of  the  basal  corpuscles  of  the 
cilia  composing  the  membranelles  and  of  a  compact  row  of  large  ecto- 
plasmic  granules  (fig.  17)  renders  this  fiber  so  obscure  that  a  distinct 
and  satisfactory  view  of  it  may  be  had  only  after  dissecting  off  the 
membranelles  and  oral  lip  and  allowing  the  ectoplasm  to  disintegrate. 
Most  of  the  lattice-work  complex  within  the  oral  lip  may  be  distinctly 
seen  in  ventral  view.  The  basal  attachments  of  this  to  the  mem- 
branelle fiber  are  indistinct  if  at  all  visible,  due  to  the  basal  corpuscles 
and  large  granules  of  the  ectoplasm. 


MOVEMENTS 

So  far  as  I  have  been  able  to  ascertain,  the  creeping  and  swimming 
movements  of  the  genus  Euplotes  have  not  been  described.  In  this 
species,  Euplotes  pa-tella,  there  are  evident  three  specific  creeping  and 
six  swimming  movements.  Of  the  latter,  two  are  much  less  common 
than  are  the  other  four. 

Being  typically  of  creeping  habit,  this  animal  is  usually  found 
moving  about  on  the  bottom  of  an  aquarium  or  over  various  debris  and 
vegetation  or  on  the  under-surface  of  scum  or  of  the  surface  film  of 
the  water.  Its  creeping  movements,  therefore,  are  readily  observable. 
This  method  of  locomotion  is  effected  by  means  of  all  the  cirri  on  the 
ventral  surface,  aided  more  or  less  by  the  ever  active  membranelles. 
The  three  kinds  of  creeping  movements  are:  (1)  locomotion  straight 
ahead  or  slightly  to  the  left  (orally),  (2)  a  quick,  backward  movement, 
usually  for  a  distance  about  equivalent  to  the  length  of  the  body,  or  less, 
and  (3)  a  turn  to  the  right  (aborally)  through  an  angle  of  thirty  to  sixty 
degrees.  Movements  2  and  3  are  comparable  with  Jennings'  "avoid- 
ing reaction."  The  accomplishment  of  movement  2  probably  involves 


Tui/lar:    \i  iir<>iii<ili»-  .\i>i><inili»i  hi   Kuwait  \  4li!) 


nil  tin-  cirri  In  some  extent  hut  chiefly  the  anal  cirri  and  adoral  mein- 
brancllrs.  as  .•x])criincnts  later  will  show.  Movement  :i  is  atVected  also 
\vitli  the  aid  of  all  cirri  and  aboral  membranclles.  but  chiefly  hy  means 
of  the  frontal  cirri,  except  when  (he  turn  is  very  rapid  and  through  a 
large  angle.  say  !IO  decrees;  then  all  the  cirri,  hut  principally  the 
frontal  and  anal  cirri  and  Hie  adoral  menibranelles,  are  brought  into 
play.  Creeping  is  rendered  impossible  upon  excising  the  anal  or  the 
frontal  cirri.  This  feature  will  he  described  later  under  the  head 
"  Kxperinieiital." 

Hii/ilntix  iMiltlltt'.t  swimming  liidiits  are  less  common  than  are  ils 
creeping  movements  hut  the  animal  utili/es  this  special  advantage  by 
no  means  iiifrci|iiently.  Also,  tlie  variety  of  its  swimming  movements 
indicates  considerable  proficiency  in  this  valuable  mode  of  locomotion. 
The  six  movements  in  swimming.  above  referred  to.  are  as  follows. 
(1)  straight  ahead  without  rotation.  (2)  straight  ahead  in  spiral 
rotation.  (3)  circus  movement  to  the  right,  without  rotation.  (4)  circus 
movement  to  Hie  left,  without  rotation,  (">)  a  sharp  turn  to  the  right, 
similar  to  creeping  movement  (3),  and  (6)  movement  directly  back- 
wards, comparable  with  creeping  movement  (2). 

It  will  be  convenient  here  to  recall  the  special,  effective  strokes  of 
the  membranelles  and  of  the  various  groups  of  cirri  :  (a)  The  elTeetive 
strokes  of  the  membranelles  may  pull  the  animal  forward  or  by  reversal 
drive  it  backward.  Without  the  interplay  of  cirri,  the  limli  »<•//  of 
direction  by  means  of  the  membranelles  is  neither  straight  ahead  nor 
straight  backwards  but  in  a  circuit,  as  will  be  shown  later,  (ft)  The 
caudal  cirri  may  function  as  rudders  or  as  propellers.  The  two  on  the 
right  usually  function  as  propellers:  the  two  on  the  left,  as  rudders. 
Griffin  (1910),  for  the  caudal  cirri  in  E.  irorecsteri,  finds  the  ten- 
dencies of  their  movement  to  be  just  the  reverse  of  those  which  I  have 
ascribed  to  corresponding  cirri  in  E.  patella,  (c)  The  anal  cirri  may 
lash  directly  backward,  individually  or  simultaneously,  and  so  drive 
the  animal  forwards;  or  they  may  lash  directly  forward,  not  always 
but  often  .synchronously,  driving  the  animal  backwards:  or  they  may 
lash  to  the  right  side  with  the  effective  stroke  backwards  or  forwards. 
thus  aiding  to  turn  the  animal  to  the  left  or  right  respectively. 
dl)  The  frontal  and  ventral  cirri  commonly  show  infundibular  move- 
ment. with  the  effective  stroke  directed  variously;  only  occasionally 
has  the  lashing,  whiplike  movement  been  observed  in  these  cirri. 

(1)  The"straight  ahead  "  swimming  movement  is  of  short  duration. 
but  occurs  rather  frequently,  particularly  after  the  animal  has  been 


430  Universi/u  of  Citliforniii  I'ltlilirulions  in  Zoology       [VOL.  19 

strongly  stimulated  mechanically,  e.g..  by  stirring  the  water  violently. 
This  movement  is  often  observed  upon  transferring  an  animal  to  the 
hanging  drop  by  means  of  a  capillary  pipette.  The  anal  and  marginal 
cirri  may  aid  in  this  movement  but  they  are  not  essential.  (Experi- 
mental evidence  will  be  given  for  this  and  following  positive  state- 
ments.) 

(2)  Spiral  movement  is  the  one  most  frequently  observed.     For 
this  movement,  the  marginal  cirri  are  not  essential,  the  anal  cirri  are 
useful  and  the  frontal  cirri  very  valuable.    "Without  the  adoral  mem- 
branelles  the  movement  normally  is  quite  impossible. 

(3)  Circus  movement  to  the  right  is  frequently  seen   after  the 
animal  has  been  confined  in  a  narrow  hanging  drop  which  may  be 
either  comparatively  deep  or  shallow.     The  anal  and  marginal  cirri 
may  aid  in  this  movement  but  they  are  quite  unessential.    The  frontal 
cirri,  particularly  the  ' '  group  of  three ' '  are  useful  here  but  the  move- 
ment is  performed  chiefly  by  means  of  the  adoral  membranelles. 

(4)  Circus  movement  to  the  left  is  so  infrequent  that  the  means  for 
its  accomplishment  have  not  been  studied.    It  has  been  observed  only 
when  the  animal  was  confined  in  a  hanging  drop. 

(5) The  sharp  turn  to  the  right  is  performed  chiefly  by  means  of  the 
adoral  membranelles  and  anal  cirri.  The  marginal  cirri  are  here  useful 
but  not  essential.  The  movement  is  very  common.  Usually  the  spiral 
movement  does  not  proceed  far  without  this  sharp  turn  intervening  to 
divert  the  animal's  course. 

(6)  The  backward  movement  is  effected  chiefly  also  by  the  anal 
cirri  and  always  concomitantly  with  the  reversal  of  the  membranelles. 
It  is  wholly  an  avoiding  reaction  and  is  distinctly  comparable  with  the 
creeping  movement  2.  Indeed,  it  may  be  regarded  as  merely  the 
augmentation  of  that  movement  2,  as  shown  by  disturbing  the  creeping 
animal  sufficiently  with  the  needle-point  or  by  applying  some  chemical, 
such  as  methylene  blue.  The  animal  may  thereupon  dash  backwards  a 
distance  several  times  its  length,  even  repeating  the  movement  again 
and  again.  In  this  respect  E.  patella  strongly  reminds  one  of  its 
relative,  Uronychia,  whose  avoiding  reaction  brings  into  play  the  large 
posterior  cirri  which  are  seldom  if  ever  otherwise  used  (Calkins,  1911, 
p.  98). 


Ta>/l<ir:  Nevromot or  Apparatus  in  /•,'//y)/o/<x  431 


EXPERIMENTAL 

'1'ln1  following  results  are  from  experiments  made  on  several 
hundred  Kui>l»tcs  patdln.  Of  those  experiments.  Ml")  weiv  recorded 
with  fairly  extensive  notes  mi  the  exact  location  and  nature  of  the  cut 
and  on  the  animal's  reactions  before,  during,  and  after  the  operation, 
allowing  several  minutes  for  its  recovery  from  the  shock  effects.  The 
various  cuts  include:  (1)  1  ransoctions  i dividing  the  animal  in  any 
piano  at  right  angles  to  its  long  axisK  i  iM  excisions  of  external 
organelles  with  or  without  a  portion  of  the  body,  and  i'8)  incisions  in 
the  liody  or  oral  lip  in  any  plane.  Efforts  were  made  also  to  ascertain 
some  of  the  physical  properties  of  the  pellicle  and  of  the  librillar 
system. 

PELLICLE 

This  membrane  which  completely  envelops  the  body  and  oral  lip  of 
Kiil>lnttx  ixilillii  is  firm,  fairly  tough,  and  sufficiently  rigid  to  main- 
tain constantly  the  normal  form  of  the  body  and  lip.  even  when  the 
animal  is  subjected  to  a  considerable  stress  from  changes  in  water-glass 
surface  tension  or  to  the  applied  pressure  of  a  flexible  needle.  Figure  1 
shows  tlie  extent  of  an  incision  fully  two-thirds  the  width  of  the  body, 
yet  this  animal  continually  kept  its  normal  shape  during  a  half-hour 
of  devious  movements  through  the  water.  In  making  dissections  the 
toughness  of  the  pellicle  requires  the  use  of  needles  with  rather  stiff, 
short  points.  Long-pointed,  very  flexible  needles  are  ineffective. 

The  extensile  property  of  the  pellicle  is  quite  obvious  in  an  animal 
which  has  gorged  itself  with  food  until  the  body  is  conspicuously 
bulged.  If  such  an  animal  be  subjected  to  a  gradually  increasing 
pressure  by  the  surface  tension  method  previously  described,  just 
sufficient  to  cause  the  egestion  of  a  few  food  particles  through  the 
pharynx,  then  as  the  needle  is  slowly  removed  the  pellicle  may  here 
and  there  become  wavy  or  wrinkled.  "Within  a  few  minutes  the 
wrinkles  usually  entirely  disappear.  The  elasticity  of  the  membrane 
may  be  readily  demonstrated  by  applying  a  fairly  flexible  needle  the 
full  width  of  the  body  when,  with  due  pressure  there  occurs  a  con- 
spicuous bending  of  the  body  over  the  needle.  Upon  releasing  the 
pressure  the  body  at  once  resumes  its  normal  shape.  This  may  be 
repeated  successively  many  times.  If.  however,  the  animal  has  been 


432  University  of  California  l'ii/i/irations  in  Zoology       [VOL.  l£ 

well  flattened  out  by  surface  tension  for  about  an  hour,  the  flatness 
persists  for  a  time  after  a  drop  of  water  has  been  added,  but  gradually 
the  body  recovers  its  normal  form,  usually  within  half  an  hour  or  less. 
During  an  incision,  short  furrows  frequently  appear  on  either  side  of 
the  needle  (fig.l).  These  may  remain  for  some  time  but  eventually 
disappear. 

Any  apparent  modification  in  the  shape  of  Euplotes  patella  occurs 
only  from  extraneous  pressure.'  That  the  animal  of  itself  is  unable  to 
vary  its  shape  may  be  observed  when  it  is  hemmed  in  by  cotton  or  silk 
fibers  partially  sealed  to  the  cover-slip.  Paramecia  in  the  same  hang- 
ing drop  force  their  way  among  the  fibers  through  narrow  passes  with 
constrictions  of  the  body,  a  feat  quite  impossible  to  E.  patella.  Further 
contrast  in  the  pellicles  of  these  two  forms  is  seen  upon  adding  a  weak 
solution  (.1  per  cent)  of  tannic  or  acetic  acid.  "Blisters"  quickly 
appear  on  Paramecium  but  not  on  E.  patella,  although  both  may  die  in 
the  solution  within  a  few  minutes. 


FIBRILLAR  SYSTEM 

Studies  of  the  fibers  and  their  relations  were  made  by  means  of 
various  dissections  but  the  most  satisfactory  observations  were  had 
when  a  slow  disintegration  of  the  body  was  brought  about  by  inducing 
delicate  changes  of  surface  tension  with  a  V-shaped  needle.  There- 
upon the  fibrillar  system  and  its  attached  organelles  would  often 
remain  intact  and  were  always  the  last  part  of  the  body  to  undergo 
disintegration. 

The  anal  cirri  fibers  normally  lie  upon  the  inner  surface  of  the 
ectoplasm  just  above  ventral  grooves  which  are  formed  by  clcarly 
defined  ridges.  Each  ridge  is  chiefly  composed  of  a  single  row  of  very 
large  ectoplasmic  granules  (fig.  20)  that  at  times  present  internally  a 
finely  granular  appearance  and  often  persist  several  minutes  after 
the  body  has  entirely  disintegrated.  Sometimes  they  have  been  seen 
to  swell  and  burst  explosively,  disappearing  entirely  from  view.  These 
and  surrounding  smaller  ectoplasmic  granules  lie  embedded  in  a 
hyaline,  gel  matrix  which  apparently  is  continuous  with  the  basal 
plates  of  the  anal  cirri.  This  region  of  ectoplasm  resists  disruption 
longer  than  the  adjacent  portions  and  so  it  frequently  happens  that 
the  anal  cirri  fibers,  which  lie  upon  the  inner  surface  of  the  ectoplasm, 
all  remain  intact  after  the  complete  disintegration  of  the  body.  This 
condition,  however,  does  not  long  prevail.  Soon  the  ectoplasm  here 


1920]  Tai/lur:  Newromotor  Apparatus  in  K<II>I<>II  x  4:i:! 

S!HI\\S  signs  of  dissolution  by  a  gradual  dispersion  of  its  granules  and 
llii'  anal  cirri  libers,  with  or  without  their  cirri  attached,  atv  at  length 
set  free,  tlicir  spatial  relations  occasionally  remaining  unchanged. 
Can- fill  observations  during  tliis  tardy  disintegration  of  cctoplasui, 
aloni:  with  tlie  explorations  by  means  of  the  needle,  make  it.  fairly  cer- 
tain that  the  anal  cirri  fibers  do  not  lie  within  the  ectoplasm  but  upon 
its  inner  surface,  being  supported  there  by  a  very  thin,  hyaloplasmic 
sheath  which  may  be  a  continuation  of  or  comparable  with  the  hyalo- 
plasmic matrix  in  which  are  embedded  the  granules  of  the  ectoplasm. 
The  critical  focus  for  a  fiber  does  not  appear  to  be  identical  with  that 
for  the  ectoplasmic  granules  along  (below)  the  fiber.  Furthermore, 
(lie  fillers  are  more  or  less  readily  displaced  by  means  of  the  needle, 
although  when  undisturbed  they  remain  adherent  to  the  ectoplasm. 

When  set  free  from  all  attachments,  the  anal  cirri  fibers  may  be 
bent  variously  with  the  needle  (fig.  15).  They  are  then  found  to  be 
fairly  flexible,  in  no  wise  brittle  and  almost  wholly  irresilient.  How- 
ever. In-fore  the  ectoplasm  has  completely  dissolved,  the  fibers  are 
much  less  flexible  and  generally  recover  after  being  bent.  Figures  14 
and  15  illustrate  several  permanent  shapes  into  which  the  fibers  were 
bent  by  means  of  the  needle.  They  may  adhere  to  the  needle  and  so 
be  pulled  about  through  the  water.  They  do  not  long  resist  dissolution 
and  so  disappear  usually  within  fifteen  minutes  or  less  time  after  their 
exposure  to  the  water. 

Apposed  dorsally  to  the  basal  plate  of  each  anal  cirrus,  the  corre- 
sponding fiber  is  modified  into  a  "fan  shaped  structure'  (Yocom,  1918) 
which  I  shall  here  designate  the  "anal  fiber  plate."  This  small  plate  is 
distinctly  rectangular  (fig.  14),  and  not  oval  as  figured  by  Yocom.  Its 
attachment  to  the  fiber  proper  is  secure,  as  may  be  readily  ascertained 
by  pulling  or  pushing  the  fiber  about  through  the  water  with  the 
needle-point.  An  interesting  and  significant  feature  is  its  intimate 
association  with  the  basal  plate  of  the  anal  cirrus.  Figure  14  is  a 
camera  drawing  of  a  cirrus  in  the  process  of  detachment  from  the 
"anal  fiber  plate."  It  will  be  observed  that  the  cirrus  has  rotated 
90  degrees  on  its  long  axis  and  that  the  gelatinous  extensile  basal  plate, 
which  is  a  highly  viscous  gel,  remains  attached  to  the  anal  fiber  plate. 
This  attached  condition  is  rarely  found,  owing  to  the  readiness  with 
which  the  basal  plate  detaches  from  the  anal  fiber  plate.  While 
attempting  to  make  this  drawing  with  the  parts  in  situ,  the  separation 
ensued  so  readily  that  I  succeeded  in  outlining  only  the  partial  detach- 
ment as  shown  in  the  figure. 


434  Unifcrnihj  of  California  Publications  in  Zoology       [VOL.  19 

Just  as  the  anal  cirri  with  their  attached  fibers  frequently  persist 
intact  after  the  remaining  cytoplasm  has  dissolved,  so  also  do  the  mem- 
branelles  with  the  membranelle  fiber  resist  immediate  disintegration. 
Furthermore,  in  seven  recorded  instances  I  have  observed  the  anal 
cirri,  their  fibers,  the  motorium,  the  membranelle  fiber,  and  the  nn  111- 
branelles,  all  remain  united  for  several  seconds  to  about  three  minutes 
after  the  disruption  of  the  body.  In  three  of  these  cases,  the  anal  cirri 
and  membranelles  continued  lashing,  but  feebly  and  for  a  few  seconds 
only. 

The  motorium  with  its  attached  jiirmbnnielle  and  anal  cirri  fibers 
has  been  distinctly  identified  after  more  or  less  complete  disintegration 
of  the  body.  Much  more  frequently,  however,  only  the  fibers  are 
evident.  It  would  appear,  therefore,  that  the  motorium  readily 
detaches  itself  from  its  connected  fibers  or  otherwise  vanishes,  perhaps 
by  rapid  dissolution.  In  its  normal  position  the  motorium  may  be 
readily  displaced  with  the  needle-point.  However,  it  resumes  its  usual 
position  upon  the  removal  of  the  needle.  But  if  it  be  pushed  too  far, 
say  ten  microns,  out  of  place  it  may  become  detached  from  its  fibers, 
or  apparently  injured  to  such  an  extent  that  it  dissolves  or  otherwise 
disappears. 

In  unstained  animals,  as  stated  previously,  the  membranelle  fiber 
may  be  distinctly  seen  only  a  short  way  from  its  attachment  to  the 
motorium.  Thereafter  it  becomes  concealed  among  the  ectoplasmic 
granules  along  the  basal  plates  of  the  membranelles  (fig.  17).  It  may 
be  observed  only  after  these  granules  have  dispersed  with  the  dissolu- 
tion of  the  ectoplasm.  Its  general  physical  properties  are  apparently 
the  same  as  those  above  stated  for  the  anal  cirri  fibers.  That  descrip- 
tion may  suffice  for  this  fiber  also. 

However,  associated  with  the  membranelle  fiber  and  membranelles, 
certain  plates  have  been  found  which  I  shall  here  call  the  "mem- 
branelle fiber  plates"  (fig.  13).  These  were  first  clearly  observed  upon 
partial  disintegration  of  the  series  of  membranelles  which  had  been 
dissected  from  an  animal  vitally  stained  for  about  eighteen  hours  in 
a  .0001  per  cent  aqueous  solution  of  haemotoxylin.  The  membranelles 
proper  had  been  set  free,  thus  exposing  these  plates,  one  for  each 
double  row  of  membranelles.  Figure  17  is  a  camera  drawing  of  the 
plates  and  the  membranelle  fiber.  The  spokelike  formation  shown  in 
the  figure  is  usually  assumed  by  the  series  of  plates  upon  detachment 
of  the  membranelles  and  disintegration  of  the  ectoplasm.  This 
arrangement  is  clearly  occasioned  by  their  individual  attachment  at 


THI/IUI':  Neufomotor  Apparatus  in  Euplotes  •!•!•"> 

only  OIK-  cud  to  the  membranelle  tilicr.  Explorations  with  Ilic  needle 
show  this  connection  to  be  fairly  secure.  Also,  the  relation  of  each 
niembranelle  tn  its  corresponding  membranelle  liber  plate  has  been 
found  to  he  the  same  as  the  relation  of  tin-  anal  cirrus  to  its  anal  fiber 
plate.  Of  this  one  may  he  fully  convinced  upon  observing  the  nicin- 
branelle  peel  from  it.s  plate,  a  process  which  occurs  not  infrequently 
about  one  minute  after  the  disruption  of  the  ectoplasm.  Thereupon, 
the  basal  plate  of  the  membraiielle,  in  which  the  basal  corpuscles  of 
the  component  cilia  and  the  ciliary  rootlets  are  imbedded,  eompletely 
sepai-ales  from  the  membranelle  fiber  plate  which,  like  the  anal  cirrus 
plate,  shows  a  smooth,  clean  surface,  with  no  evidence  of  any  ciliary 
rootlets  having  been  attached. 

The  "dissociated  libers"  described  by  Yocom  (1IMS)  as  radiating 
at  the  base  of  each  of  the  thirteen  cirri  (i.e..  excluding  the  anal  cirri). 
have  been  found  to  be  definitely  connected  with  a  plate  somewhat 
similar  to  the  anal  cirri  plate,  although  of  a  shape  (fig.  21)  correspond- 
ing to  that  of  the  base  of  the  cirrus.  These  were  first  observed  upon 
the  disintegration  of  an  animal  likewise  .stained  with  a  .0001  per  cent 
auctions  solution  of  hacmatoxylin.  Several  radiating  fibers  were  dis- 
tinctly seen  to  be  united  to  each  plate.  As  yet.  T  have  not  definitely 
observed  the  separation  of  one  of  these  plates  from  its  cirrus.  Indica- 
tions in  two  cases  where  the  separation  was  almost  complete  point 
toward  a  relation  between  cirrus  and  plate  here  that  is  similar  to  the 
relation  of  an  anal  fiber  plate  to  its  corresponding  cirrus.  I  shall 
designate  these  plates  the  "dissociated  fibers  plates."  Kiiru res  21  and 
~2}/i  show  several  such  plates  from  the  same  organism  which  vary 
slightly  in  sixe  and  shape.  These  variations  are  apparently  common. 

TRANSECTIONS 

Hitirii  n  /In  "i/rmij)  itf  tltr/i"  and  "i/rnup  of  ftiitr"  frtnilnl  rirri 
i  lig.  2). — The  anterior  part  of  the  animal  swims  rapidly  (of.  swim- 
ming movement  :i.  p.  42!)).  the  inner  side,  that  with  the  three  frontal 
cirri,  performing  a  small  circle  and  the  opposite  side  a  correspondingly 
larger  one.  This  performance  continues  the  same  after  more  water  is 
added  to  the  hanging  drop.  The  part  infrequently  revolves,  as  on  the 
IOULT  axis  of  the  normal  animal,  and  it  occasionally  reverses  the  effect  ivo 
stroke  of  the  membranelle.s  to  drive  itself  a  short  distance  backwards 
(cf.  swimming  movement  6,  p.  429).  In  either  case  the  circus  move- 
ment to  the  right  is  soon  resumed  and  continues  with  few  such  inter- 
ruptions until  the  part  apparently  becomes  fatigued  and  dies.  Death 


436  University  of  California  l'ul>Hc<iH»ns  in  Zoology       [VOL.  19 

generally  results  within  an  hour  after  the  transection,  but  in  three 
cases  this  ceaseless  activity  continued  for  more  than  four  hours.  Any 
indications  of  regeneration  have  not  been  observed. 

The  posterior  piece  is  much  less  active.  It  usually  swims  straight 
ahead  and  occasionally  in  circuits  to  the  right  (cf.  swimming  move- 
ments 1  and  3,  p.  428)  and  very  frequently  revolves,  then  with  obvious 
difficulty,  on  the  long  axis.  It  remains  most  of  the  time  inactive, 
seldom  creeps  and  always  very  slowly  and  feebly,  and  responds  more 
or  less  readily  to  jarring  or  to  stimuli  effected  by  the  needle-point.  In 
the  latter  case  its  anterior  end  is  very  little  if  any  more  sensitive  than 
other  parts  of  the  body.  A  distinct  avoiding  reaction  (cf.  swimming 
movement  6,  and  creeping  movement  2,  p.  428)  has  at  no  time  been 
observed.  Use  of  the  frontal  and  marginal  cirri  is  conspicuously  more 
normal  than  is  its  use  of  the  anal  cirri,  especially  when  attempting  to 
creep,  as  on  the  under  surface  of  the  inverted  cover-slip. 

Experiment  106  (fig.  2). — Anterior  piece  swims  very  rapidly  in  right  circus 
movement  with  the  three  frontal  cirri  as  a  "moving  center."  Occasionally  it 
whirls  and  tumbles  deviously  about;  it  may  then  swim  straight  ahead  revolving 
two  or  three  turns  on  its  long  axis,  but  very  soon  returns  to  circus  movements. 
It  very  seldom  reverses  the  effective  stroke  of  membraneles,  even  when  needle 
is  thrust  in  its  way.  Frontal  cirri  beat  continually  as  also  do  the  membranelles. 

Posterior  part  mostly  at  rest  with  occasional  movements  of  frontal  and 
marginal  cirri  less  often  of  the  anal  cirri,  except  when  another  E.  patella  runs 
into  it;  then  it  dashes  for  a  short  distance  usually  straight  ahead.  It  then 
bumps  into  piece  of  debris  which  it  pushes  straight  ahead  but  does  not  go  far. 
Jarring  starts  its  movements,  which  soon  cease.  Anal  cirri  are  commonly 
moved  upon  any  lashing  of  the  other  cirri  which  is  sufficient  to  move  the  body. 
It  would  appear  that  they  initiate  such  movement,  which  is  then  taken  up  by 
the  anal  cirri.  When  stimulated  with  a  needle  point,  its  anterior  end  is  little 
if  any  more  sensitive  than  are  the  sides  or  posterior  end. 

Transection  just  posterior  to  the  "group  of  four"  frontal  cirri 
(fig.  3). — Anterior  part  swims  in  circus  movements,  although  some- 
what less  completely  than  does  the  anterior  piece  above  described.  It 
resorts  more  frequently  to  rotation  on  the  long  axis  and  to  the  reversal 
of  the  organelles  to  drive  the  part  backwards,  although  here,  too,  the 
' '  rotation ' '  movement  is  more  common  than  the  reversal  reaction.  The 
part  never  creeps  but  swims  rapidly  and  continuously  for  hours  after 
the  operation.  It  does  not  turn  sharply  to  the  right  (cf.  swimming 
movement  5,  p.  429 )  and  very  seldom  shows  the  avoiding  reaction  upon 
being  stimulated  by  the  needle.  After  several  hours  the  part  may  come 
to  rest  on  debris,  on  the  surface  film  of  the  water  or  on  the  cover- 
glass.  It  is  then  generally  very  sensitive  to  slight  jarring  or  other 
mechanical  stimuli,  whereupon  its  rapid  swimming  may  be  resumed 


''•'-'"  I  Tut/lor:   Nevromot or  Apparatus  in  Hni>!ut/s  4:57 

for  long  periods.  Its  oral  lip  is  m<>iv  sensitive  to  a  stimulus  by  the 
needle-point  than  are  the  membraiielles  over  the  oral  lip.  or  its  pos- 
terior.  cut  surface,  or  the  frontal  cirri  or  any  other  part. 

The  posterior  part  is  generally  very  much  less  active.  However,  in 
ten  recorded  instances  this  piece  revolved  on  its  cut  surface  as  an  axis 
exceedingly  rapidly  i  about  two  revolutions  per  second  >  for  a  half 
minute  or  less  just  after  the  transect  ion  was  completed.  'Phis  revolv- 
ing performance.  generally  at  a  much  slower  rate,  is  a  common  reaction 
of  the  posterior  piece  following  this  operation.  The  direction  of  these 
rexolutions  is  clockwise  when  viewed  from  the  left  side.  For  some 
time  after  the  cut  is  made  the  anal  cirri  are  quite  active  with  their 
etl'cctive  stroke  in  such  a  way  as  chiefly  to  induce  the  revolutions,  '['his 
part  swims  in  circus  movements  to  the  right  infrequently  and  very 
seldom  rotates  on  the  long  axis;  when  it  does  so,  it  moves  quite 
clumsily  and  imperfectly.  Within  about  an  hour  movement  ceases.  It 
is  then  much  less  responsive  to  mechanical  stimuli  than  is  the  anterior 
part,  after  coining  to  rest.  When  thus  stimulated  its  movements,  which 
are  for  the  most  part  revolutions,  are  effected  chiefly  by  means  of  the 
two  ventral  and  the  two  right,  fimbriated  marginal  cirri,  the  anal  cirri 
remaining  more  or  less  passive. 

Experiment  209  (fig.  3). — Anterior  part  swims  violently  in  various  devious 
movements,  sometimes  rotating  on  the  Ion;;  axis  or  reversing  to  swim  a  short 
distance  backwards,  but  most  of  time  it  moves  in  right  circus  movements.  This 
r-casrlfss  swimming  continued  from  11:50  A.M.  until  about  5  P.M.,  when  its  move- 
ments were  considerably  slower,  and  at  5:30  P.M.  the  part  was  resting  on  debris. 
Readily  responded  to  touch  of  the  needle  point  against  the  oral  lip,  but  less  so 
when  the  adoral  membranelles,  frontal  cirri  or  posterior  cut  surface  was  simi- 
larly stimulated.  Slight  jarring  induced  violent  swimming,  which  lasted  about 
thirty  seconds,  after  which  it  again  became  quiet.  At  this  time  rotation  on  the 
long  axis  was  more  common  than  previously.  Following  morning,  this  part  bad 
died. 

Posterior  part  not  very  active  from  the  first.  Anal  cirri  beat  slowly,  irregu- 
larly and  with  little  effectiveness.  Occasionally  swam  in  circus  movement  to 
the  right  and  sometimes  showed  imperfect  rotations  on  the  long  axis,  but  more 
often  its  movements  were  revolutions  about  the  cut  surface  as  an  axis.  Within 
forty  minutes,  it  had  become  passive,  the  two  right  marginal  cirri  infrequently 
showing  movements  which  were  always  infundibular  but  without  effect.  Only 
slightly  responsive  to  jarring,  then  generally  revolved  as  before  but  very  few 
times,  after  which  it  again  became  quite  inactive.  These  revolutions  were 
effected  mainly  by  the  two  right,  fimbriated  marginal  cirri  with  infundibular 
movement;  the  two  on  the  left  lashed  with  the  effective  stroke  upward,  thus 
inducing  the  revolutions.  The  two  ventral  cirri  were  active  most  of  the  time, 
also  showing  conspicuously  the  infundibular  type  of  movement.  The  anal  cirri, 
on  the  other  hand,  were  mostly  inactive;  irregularly  one  or  two  might  lash 
feebly,  but  never  more  than  one  at  a  time.  Their  effective  stroke  was  always 
backward,  therefore  tending  to  aid  the  part  in  its  rotations  clockwise  as  viewed 
from  the  left.  This  part  also  died  within  about  thirty-six  hours. 


438  University  of  California  Publications  in  Zoology       [VOL.  19 

Between  the  two  ventral  a  ml  ju-c.  anal  cirri  (fig.  4). — Hero,  the 
movements  of  the  anterior  piece  are  quite  similar  to  those  of  the  same 
part  described  just  previously.  There  is,  however,  less  tendency  to 
swim  in  circuits  to  the  right  .-mil  spiral  swimming  movements  are  con- 
siderably more  frequent.  Indeed,  in  the  two  respects  just  mentioned, 
this  part  closely  approximated  the  corresponding  swimming  movements 
of  the  normal  animal.  There  are,  on  the  other  hand,  some  notable 
differences:  (1)  Avoiding  reactions  (swimming  movement  6,  p.  429) 
are  seldom  observed  even  when  the  oral  lip  region  is  strongly  stimu- 
lated by  means  of  the  needle,  or  when  some  disagreeable  solution,  such 
as  methylene  blue,  is  introduced.  (2)  Creeping  is  very  infrequently 
attempted  and  is  conspicuously  more  or  less  impossible.  In  a  few  cases. 
the  piece  has  been  observed  to  crawl  slowly  and  awkwardly  for  a  short 
distance  over-debris  or  along  the  needle,  but  this  ability  is  distinctly 
impaired.  (3)  Sharp  turns  to  the  right  have  not  been  seen.  Tortuous, 
random  movements  that  involve  turning  both  to  the  right  and  to  the 
left  are  sometimes  resorted  to  but  these  are  readily  distinguishable 
from  the  short,  sharp  turns  to  the  right  which  are  common  for  the 
normal  animal  (swimming  movement  5,  p.  429).  (4)  The  creeping 
"avoiding  reaction"  (number  2,  p.  429)  has  at  no  time  been  observed 
even  when  mechanical  stimuli  are  applied. 

The  principal  characteristic  movement  of  this  posterior  piece  is  its 
rotating  on  the  cut  surface  as  an  axis,  a  rotation  which  is  not  uncom- 
monly very  rapid  (two  or  three  times  per  second)  following  the  com- 
pletion of  a  transection.  This  performance  is  of  brief  duration  and 
the  piece  comes  to  rest  on  the  surface  film  of  the  hanging  drop  or  upon 
debris.  Thereafter,  it  is  usually  very  irresponsive  to  mechanical  or 
chemical  stimuli.  If  aroused,  its  revolving  movements  are  performed 
chiefly  by  means  of  the  marginal  cirri,  the  anal  cirri  functioning 
individually  and  spasmodically,  or  not  at  all.  But  previously,  just 
after  the  operation,  the  anal  cirri  were  very  active  and  mostly  respon- 
sible for  the  rapid  revolutions.  Imperfect  circus  movements  to  the 
right  and  aboral  spiral  movements  are  quite  uncommon  for  this  part. 
These  have  never  been  observed  after  the  marginal  cirri  were  excised, 
as  a  later  experiment  will  show. 

Experiment  160  (fig.  4). — Anterior  piece  immediately  swims  in  circus  move- 
ments to  right,  but  as  often  or  more  often  moves  in  aboral  spiral  straight  ahead. 
Sometimes  performs  winding,  devious  movements  but  returns  to  spiral  swimming 
or  to  circus  movements.  During  ten  minutes  it  reversed  three  times  to  swim  a 
short  distance  backwards;  this  reaction  fairly  normal.  Two  hours  later,  resting 
on  d4bris.  Very  responsive  to  jar,  also  to  needle.  Oral  lip  much  more  sensitive 
than  membranelles,  cirri,  or  any  part  of  the  body.  Slowly  and  awkwardly 


Tiifilnr:  Neuromot or  Apparatus  in  Kit/ilo/ix  4:i'.i 

\l    a    short     di~;  r     debris.       l>oes     nut     show     creeping     • '  a\ oidinj; 

tion"   when    stimulated    with   needle .]M>int    or   by    means   of    methylene   blue. 

Also,  :i|ijil'n>i|   \\eak   acetic  acid,  when  part   swain  straight  forward,  then  reversed 

the   effective   stroke  of   orjianelles,   swimming    backwards    a    short    distance,   but 

swain    in   circuit   or   in   spiral   apparently   beyond   tlie   influence  of  the   acid 

solution. 

Posterior  part  turned  over  and  over  very  rapidly,  two  times  per  second,  with 
::rface  as  axis.  This  continued  about  twelve  minutes.  Slowed  and  came 
to  rest  on  Mirface  til'"  of  han<.'in<r  drop.  Half  hour  later,  very  irresponsive  to 
jarring  or  needle  point.  Aroused  anil  for  few  seconds  revolved  as  before,  but 
very  slowly  and  chiefly  by  means  of  the  marginal  cirri.  Anal  cirri  mostly 
passive  or  individually  and  irregularly  active.  Auain  came  to  rest.  From 
jarring,  slowly  moved  in  circuit,  very  awkwardly,  by  irregular  pushing  of  one 
or  two  anal  cirri;  other  anal  cirri  were  passhe. 


EXCISIONS 

If <  mural  of  oral  lip  with  adorn/  mi  mbraiti  Ilix. — Anterior  piece 
always  shows  one  and  only  one  reaction,  viz.,  circus  movement  to  the 
right.  This  movement  is  very  rapid  and  continues  until  the  part 
becomes  fatigued  and  dies,  which  generally  occurs  within  fifteen  min- 
utes or  less  after  the  excision.  The  effective  stroke  of  the  mem- 
branelles  is  the  same  here  a.s  when  the  normal  animal  swims  in  a  circuit 
or  spirally  straight  ahead.  In  many  specimens  observed,  there  was  at 
no  time  any  indication  of  the  reversal  of  membranelles,  and  the  path 
of  the  circuit  was  continuously  about  the  same.  This  part  did  not 
possess  the  motorium. 

The  reactions  of  the  posterior  part  are  mostly  very  similar  to  those 
described  for  the  same  part  when  a  transection  was  made  between  the 
"group  of  three"  and  "group  of  four"  frontal  cirri.  In  the  former, 
however  there  are  present  the  "group  of  three"  frontal  cirri  and  the 
motorium.  This  piece  is  able  to  creep  fairly  normally  and  in  a  few 
instances  gave  the  creeping  "avoiding  reaction."  although  the  anterior 
end  here  was  much  less  sensitive  than  the  oral  lip  of  a  normal  form. 
Swimming  is  uncommon  and  abnormal.  Spiral  rotations  on  the  long 
axis  are  infrequent  and  quite  imperfect.  The  part  more  frequently 
revolves  with  the  cut  surface  as  an  axis,  but  this  movement  is  generally 
combined  with  a  sort  of  spiral  movement  on  the  long  axis.  Of  five 
such  posterior  parts  carefully  observed,  one  regenerated  an  oral  lip 
after  budding  off  about  twenty  microns  of  its  anterior  end;  the  bud, 
containing  three  frontal  cirri,  was  more  or  less  spherical,  quite  active 
for  about  an  hour,  but  died  some  time  during  the  night.  The  other 
four  of  these  five  regenerated  normally  but  only  after  eighteen  to 
thirty  hours. 


440  University  nf  ('tili(<>rni<i  Publications  in  /»<>!ni/ii       [VOL.  19 

Removal  of  marginal  cirri. — These,  due  to  their  exposed  position, 
were  readily  snipped  off  with  the  needle.  The  excised  parts  thereafter 
wire  never  observed  to  beat.  But  when  one,  two,  three  or  all  were 
removed  with  some  of  the  body  plasm  the  cirri  continued  lashing  very' 
rapidly  and  driving  the  piece  deviously  through  the  water  until  death, 
which  followed  a  few  minutes  later.  "When  an  excision  (properly, 
a  transection)  of  the  caudal  end  was  made  to  include  all  four  marginal 
cirri,  the  piece  revolved  very  rapidly  with  the  cut  surface  as  an 
axis  but  in  such  manner  as  to  move  speedily  through  the  water  with 
the  left  side  foremost.  Such  removal  or  the  snipping  off  of  some 
or  all  of  these  cirri  did  not  apparently  modify  the  several  swimming 
or  creeping  movements  of  the  normal  animal.  If,  however,  these  cirri 
had  been  removed  from  an  animal  which  was  then  transected  just 
anterior  to  the  anal  cirri,  the  posterior  part  usually  rotated  rapidly, 
the  cut  surface  as  its  axis,  for  several  minutes.  Circus  or  spiral 
movements  were  at  no  time  observed.  But  within  an  hour  after 
becoming  quiet  it  was  irresponsive  to  mechanical  stimuli  and  did  not 
resort  to  rotating  movements  again.  The  anal  cirri  lashed  feebly, 
very  irregularly  and  ineffectively. 

Excision  of  frontal  cirri. — Owing  to  the  length  of  these  cirri  and 
the  extension  of  four  of  them  beyond  the  right  lateral  margin  of  the 
body  the  four  may  be  snipped  off  with  a  V-shaped  needle.  Thereafter, 
the  animal  very  seldom  attempts  creeping  and  its  spiral  movements 
are  abnormal.  In  the  latter  instance,  its  anterior  end  rotates  in  a 
larger  spiral  than  that  of  the  posterior  end.  In  two  cases  all  but  one 
frontal  cirrus  were  either  snipped  off  or  removed  by  inserting  the 
needle-point  at  the  base  of  each  cirrus,  thus  to  gouge  them  loose.  These 
cirri  came  off  rather  readily.  Three  of  them  beat  several  times  follow- 
ing their  detachment.  In  each  case  the  animal  could  not  creep,  but 
frequently  swam  slowly  in  circuits,  or  in  spiral  movements  with  the 
anterior  end  describing  spirals  which  were  about  twice  the  diameter 
of  those  of  the  posterior  end.  No  discernible  injury  resulted  from 
gouging  out  these  cirri ;  the  movements  of  both  the  membranelles  and 
anal  cirri  were  apparently  normal.  In  a  few  instances,  the  animal 
gave  the  avoiding  reaction  upon  stimulation  of  the  oral  lip  with  the 
needle-point,  although  these  were  feeble  and  abnormal.  However,  both 
animals  died  within  forty-eight  hours  without  regenerating  new  frontal 
cirri.  Their  death  may  have  been  due  directly  to  injuries  from  the 
excisions  or  indirectly  to  infections  or  other  causes. 

Excision  of  anal  cirri. — Infrequently,  E.  patella  were  found  with 
fully  half  of  the  anal  cirri  extending  beyond  the  caudal  margin  of  the 


Ttiiiliir:  Neuromotor  Apparatus  in  l-'ii/iiiitis  111 

liody.  Ill  several  eases  the  anal  cirri,  to  about  two-thirds  of  their 
length,  tin'  marginal  cirri  and  a  small  piece  of  the  caudal  end  of  the 
body  were  excised.  Creeping  was  thus  made  practically  impossible, 
the  animals  resorted  more  frequently  to  circus  movements  to  the  right, 
and  sharp  turns  to  the  riirht  were  not  evident.  Spiral  revolution  on 
the  long  axis  was  apparently  normal.  Four  such  animals  regenerated 
the  excised  parts,  including  the  anal  cirri. 

Several  attempts  were  made  to  ironic  off  the  anal  cirri  just  as  the 
frontal  cirri  had  been  removed.  In  two  experiments  '  nos  l>1f>  and 
I'll!)  all  the  anal  cirri  were  successfully  removed,  with  little  or  no 
injury  to  the  body.  In  each  case,  there  followed  several  significant 
results :  (1)  the  animal  was  unable  to  creep.  (2)  it  did  not  turn  sharply 
to  the  right.  (3)  the  avoiding  reaction  was  never  observed,  and  (4) 
circus  movements  to  the  right  wore  performed  more  frequently. 

Experiment  I'M'.. —  Kemoved  anal  i-irri  4  and  ."  (see  p.  ILM).  Released  the 
animal  by  adding  water  to  tin1  hanging  drop.  It  then  performed  all  the  major 
swimming  and  creeping  movements,  including  the  avoiding  reaction. 

Again  drew  off  tin1  water  and  removed  the  remaining  anal  cirri.  1'pon  adding 
more  water  the  animal  was  observed  to  revolve  in  spirals  on  the  long  axis  and 
to  swim  in  circuits  to  the  right,  but  at  no  time  was  it  seen  either  to  creep,  to 
turn  sharply  to  the  right,  or  to  give  the  avoiding  reaction.  Its  efforts  to  creep 
on  the  under  side  of  the  cover-glass  were  unsuccessful,  the  posterior  end  being 
suspended  so  as  to  incline  the  body  at  an  angle  of  about  30  degrees  with  the 
cover-slip. 

INCISIONS 

Tlii-mii/li  lln  nral  lip  ifitliout  riittiiii/  Ike  cytostomal  fiber. — There 
was  no  apparent  decrease  in  the  sensitivity  of  any  part  of  the  oral  lip. 
and  no  change  in  the  normal  movements  and  functioning  of  the  adoral 
membranelles.  The  results  were  wholly  negative.  The  cut  usually 
healed  completely  within  an  hour. 

Through  Ihe  oral  ///>.  xri-iriiti/  tin  i-iitoxlonuil  fiber  (fig.  5). — Iri 
seventeen  cases  there  resulted  abnormal  swimming  movements  and 
distinct  changes  in  the  movements  of  the  niembranelles  on  either  side 
of  the  incision:  (1)  the  progress  of  the  animal  forward  was  impeded, 
(2)  in  its  spiral  revolutions,  commonly  the  anterior  end  described  a 
wide  spiral,  (3)  circus  movements  to  the  right  were  markedly  less 
common  as  was  also  (4)  the  occurrence  of  the  avoiding  reaction,  and 
.">  periods  of  quiet  were  more  frequent  and  of  much  longer  duration. 
I  "pon  examining  with  high  power  the  movements  of  the  memhranelles. 
a  difference  in  rhythm  was  frequently  conspicuous  between  the  series 
on  the  left  side  of  the  cut  and  those  on  the  right  side.  The  former 


442  University  of  California  Publication*  in  /Wm/i/       [VOL.  HI 


were  always  active  with  that  effective  stroke  which  normally  tends  to 
drive  the  animal  forward.  The  membranelles  on  the  right  side  of  the 
cut  occasionally  moved  in  coordination  with  the  former  or  sometimes 
did  not  move  in  the  least  but  projected  straight  out  from  their  bases. 
Not  infrequently,  they  were  distinctly  seen  to  beat  with  the  effective 
stroke  in  the  opposite  direction  to  that  of  the  series  on  the  left  side  of 
the  cut.  Carmine  granules  or  india  ink  which  had  been  introduced 
into  the  water  clearly  indicated  these  three  changes  in  the  behavior  of 
the  adoral  membranelles  on  the  right  side  of  the  cut.  It  will  be  noted 
that  the  membranelle  fiber  at  the  base  of  these  membranelles  on  the 
right  side  of  the  incision  was  continuous  and  in  connection  with  the 
motorium.  These  results  of  such  experiments  wrere  very  obvious  and 
remarkably  uniform. 

Incision  through  the  membranelle  fiber  at  any  point  posterior  to 
the  oral  lip  (fig.  6).  —  Differences  between  the  rhythm  and  direction  of 
the  effective  stroke  of  the  membranelles  anterior  to  the  incision  and 
of  those  posterior  were  apparently  identical  with  those  just  described 
above.  However,  the  swimming  movements  following  such  incisions 
were  practically  normal.  Some  animals  (three  especially  were  noted) 
were  less  active  after  the  incision  and  showed  more  tendency  toward 
circus  movements;  otherwise,  their  swimming  and  creeping  reactions 
were  comparatively  normal. 

Incisions  on  the  right  or  left  side  or  at  the  posterior  end  did  mil 
sever  the  cytostvmal  fiber  or  any  of  the  anal  cirri  fibers.  —  Following 
such  incisions  made  in  many  animals  at  various  angles  through  the 
macronucleus  or  not  (figs.  10-12)  I  have  never  as  yet  observed  any 
noteworthy  change  in  their  normal  swimming  or  creeping  reactions  or 
in  the  perfect  coordination  between  the  series  of  membranelles  and  the 
anal  cirri. 

Incisions  severing  all  the  anal  cirri  fibers.  —  Incisions  were  made 
(1)  on  the  right  side  between  the  group  of  three  and  the  group  of 
four  frontal  cirri  (fig.  7)  ;  (2)  on  the  right  side  between  the  group  of 
four  frontal  cirri  and  the  two  ventral  cirri  (fig.  8)  ;  and  (3)  on  the 
right  side  between  the  two  ventral  cirri  and  the  five  anal  cirri  (fig.  91). 

After  severing  the  anal  cirri  fibers  at  any  one  of  these  three  regions, 
two  significant  changes  were  evident  in  creeping  and  three  in  swim- 
ming movements:  (1)  there  was  distinctly  less  tendency  to  creep;  the 
animal  when  not  swimming  was  more  frequently  found  quiet  on  the 
surface  of  the  cover-slip,  on  the  surface  film  of  the  hanging  drop  or 
upon  debris.  But  when  creeping,  the  anal  cirri  were  used  with  less 
sureness  and  facility  than  normally.  That  much  was  commonly  evident 


'/'<;///</;•.•  Newomot or  Apparatus  in  Kuplotes  443 

upon  careful  observation.  Nevertheless,  the  lack  of  coordinated  move- 
ment between  the  frontal  ami  ventral  and  the  anal  cirri  (these  being 
the  animal's  creeping  feet),  was  not  at  all  times  conspicuous.  In  some 
.•a.srs  (four  recorded  instances),  this  coordination  was  apparently 
abonl  normal.  Even  here,  however,  it  was  obvious  that  the  frontal  cirri 
sometimes  initiated  the  movement  which  was  then  taken  up  by  the  anal 
cirri,  but  this  succession  was  not  always  evident;  (2)  the  avoiding 
ivartion  was  very  seldom  observed.  If  the  oral  lip  were  touched  by 
the  needle-point  (a  stimulus  which  normally  induces  the  avoiding 
reaction)  the  incised  animal  would  infrequently  give  this  reaction,  but 
more  often  would  turn  to  the  right  anteriorly  (cf.  third  creeping 
movement,  p.  428).  thus  avoiding  the  stimulus  without  performing  the 
preliminary  backward  movement  (cf.  second  creeping  movement, 
p.  428).  The  three  notable  changes  in  swimming  movements  after  the 
incision  were:  (1)  A  tendency  to  swim  in  circuits  to  the  right.  This 
ivartion  was  particularly  noticeable  just  after  the  incision  was  com- 
pleted, when  it  became  for  a  time  the  only  swimming  movement.  The 
tendency,  nevertheless,  persisted  even  until  the  wound  was  more  or 
less  fully  healed.  (2)  Sharp  turns  to  the  right  were  quite  infrequent 
and  in  a  few  cases  were  at  no  time  observed  (three  of  these  were 
recorded).  This  movement  is  effected  chiefly  by  a  strong,  quick  lash 
of  the  outermost  three  or  all  five  anal  cirri.  The  performance  of  this 
stroke  is  possible  for  these  anal  cirri  after  the  fibers  are  cut,  as  will 
later  be  shown,  but  apparently  such  strokes  are  not  readily  or  simul- 
taneously linked  up  with  corresponding  beats  of  the  membranelles ; 
(3)  The  backward  swimming  movement  (number  6,  p.  429)  has  not  been 
definitely  observed,  as  yet,  in  any  of  these  incised  animals,  even  when 
stimulated  mechanically  by  means  of  the  needle  or  chemically  with 
such  reagents  as  methylene  blue  or  acid  solutions.  In  one  instance, 
this  or  a  similar  reaction  was  apparent,  but  of  this  I  could  not  make 
certain.  It  occurred  upon  adding  a  solution  of  methylene  blue  with  a 
needle  pipette.  The  movement  backward  was  only  a  short  distance, 
two  or  three  times  the  animal's  length;  this  was  followed  by  rapid 
circus  movements  to  the  right  and  was  not  repeated,  as  is  usually  the 
case  with  a  normal  E.  patella. 

Cutting  the  anal  cirri  fibers  or  the  membranelle  fiber  or  both  near 
the  motoriuni,  or  destroying  the  motorium. — The  general  effects  upon 
swimming  or  creeping  movements  were  definite,  fairly  constant,  and 
much  the  same  after  performing  any  of  these  incisions.  These  move- 
ments have,  in  fact,  already  been  described  in  the  foregoing  paragraph. 
It  is  important,  therefore,  to  note  that  the  destruction  of  the  motorium 


444  University  of  California  Publications  in  Zoology       [VOL.  19 

by  means  of  the  needle-point  produces  modifications  in  the  animal's 
several  movements  which,  so  far  as  I  have  yet  been  able  to  ascertain, 
do  not  differ  markedly  from  the  effects  that  follow  severing  the  mem- 
branelle  fiber  or  the  anal  cirri  fibers  or  both  near  the  motorium,  or 
the  anal  cirri  fibers  at  any  point.  There  is,  then,  no  certain  evidence 
from  these  experiments  that  the  function  of  the  motorium  is  more 
specific  than  that  of  its  attached  fibers.  These  negative  results  may 
be  attributable,  however,  to  faulty  or  insufficient  technique.  On  the 
other  hand,  the  differences  in  the  behavior  of  the  membranelles  on  the 
left  and  right  sides  of  the  incision  severing  the  membranelle  fiber, 
which  were  previously  described,  might  indicate  there  some  role 
peculiar  to  the  motorium. 

Perhaps  the  clearest  evidence  for  the  want  of  coordination  and  of 
concomitancy  of  movements  between  the  membranelles  and  anal  cirri 
appeared  in  these  incised  animals  upon  supporting  one  of  them  against 
the  under  surface  of  the  cover-glass  with  a  very  flexible  needle.  To 
the  hanging  drop  had  been  added  a  trace  of  india  ink  or  a  carmine 
solution ;  thereupon,  any  changes  in  the  direction  of  the  effective  stroke 
either  of  the  anal  cirri  or  of  the  membranelles  were  quite  conspicuous 
in  the  corresponding  movements  of  the  particles  of  india  ink  or  of 
carmine.  Infrequently  the  carmine  granules  were  driven  in  the  same 
direction  by  the  membranelles  and  by  the  anal  cirri,  and  the  effective 
stroke  of  these  organelles  varied  synchronously.  This  concomitancy 
however,  did  not  long  continue.  Their  phases  of  rhythm,  it  would 
seem,  changed  so  that  now  while  the  membranelles  were  driving  some 
particles  anteriorly,  other  particles  were  being  driven  posteriorly  by 
the  anal  cirri,  or  vice  versa.  These  changes  were  conspicuous  and 
frequent. 


DISCUSSION 

These  experimental  studies  have  yielded  some  evidences  on  the 
nature  of  organelle  movement  in  Euplotes  patella  which  are  here 
worthy  of  consideration.  The  significance  of  the  general  problem  of 
ciliary  structure  and  movement,  probably  due  to  the  prevalence  of 
cilia  in  both  protistan  and  metazoan  organisms,  was  early  recognized 
(Stuart,  1867)  and  has  occasioned  the  writing  of  a  large  literature, 
most  of  which  has  been  reviewed  by  Putter  (1903),  Prenant  (1914), 
and  Saguchi  (1917) .  Aside  from  minor  modifications,  the  structure  of 
cilia,  wherever  found,  appears  much  the  same.  A  cilium  is  composed 


Tat/lor:    \ "<  iir<>iin>/nr  A  i>i>«nit  ux  in   Kiijilnl,  \  44") 

of  two  different  parts  .Maier.  1903),  an  clastic  axial  lilaineiit  covered 
by  a  sheath  which,  according  to  Khainsky  ,  1!U(M.  is  continuous  with 
the  pellicle.  Kach  ciliuin  arises  from  a  basal  granule  situatc<l  in  the 
cct.iplasm  beneath  tin-  pellicle  :  1'iittcr.  1IKI4K  The  theory  of  Ilenne- 
U'liy  and  Lenhossek.  that  this  granule  in  mcta/oan  cells  is  a  derivative 
of  the  ceiitriole.  has  recently  been  opposed  by  Sairuchi  (1917),  who 
regards  the  granules  as  having  their  origin  in  mitochondria.  Con- 
tinued from  each  basal  granule  into  the  cell-plasm  is  a  fibril,  the  ciliary 
rootlet,  which  in  certain  ciliates  has  been  I'ound  to  unite  with  other 
such  rootlets  by  means  of  a  basal  fibril  riinnint:  parallel  to  the 
periphery  beneath  each  row  of  cilia  (Maier.  UN):!).  In  flagellates, 
the  basal  granule  or  blepharoplast  may  show  two  such  rootlets,  one 
uniting  the  blepharoplast  to  the  nucleus  and  the  other  connecting  the 
blepharoplast  and  parabasal  body  (Swexy.  19KH. 

The  component  cilia  of  the  cirri  and  membranelles  in  l-'.tij>lntes 
/«;/<//</  clearly  possess  each  a  basal  granule  and  ciliary  rootlet  i  tig.  17). 
As  previously  stated,  the  granules  and  rootlets  lie  within  the  basal 
plate  of  each  cirrus  and  inembrauelle.  which  in  turn  is  united  to  the 
corresponding  fiber  plate.  There  is.  as  yet.  no  evidence  that  the  ciliary 
rootlets  are  united  to  the  fiber  plate  and  they  are  here  regarded  only 
as  contiguous  with  that  plate.  The  ease  with  which  the  basal  plate 
detaches  from  the  liber  plate  and  the  want  of  indications  on  its  surface 
that  there  were  ciliary  attachments  favor  this  interpretation. 

As  regard  the  movement  of  cilia,  there  appears  in  the  literature 
a  considerable  difference  of  opinion  as  to  how  this  movement  is  pro- 
duced. Certain  investigators  regard  the  cilium  as  wholly  passive,  its 
movement  being  effected  either  by  way  of  the  basal  granule  (Hennc- 
guy.  1898 ;  Lenhossek,  1898 ;  Peter.  1899 ;  Joseph.  1903 ;  Saguchi.  1917) , 
or  by  the  contractility  of  the  ciliary  rootlets  (Simroth.  1876;  Benda. 
1899).  There  are  others  who  believe  the  cilium  itself  to  be  active 
(Engelmann.  1879;  Klebs,  1881;  Biitschli,  1885;  Schilling,  1891; 
Fischer.  1894;  Kolsch.  1902;  Prowazek.  190H;  1'iittcr.  190:{:  (iurwitz. 
1904;  Erhard,  1910;  Kolacev.  1910).  Its  power  of  contractility  lies 
either  in  the  axial  filament  or  in  the  protoplasmic  sheath  surrounding 
the  filament. 

Favoring  the  latter  view  are  the  observations  of  several  authors 
who  have  noted  that  cilia  may  continue  to  contract  after  they  have 
become  detached.  Klebs  (1881)  saw  in  the  long  flagella  of  Trachcln- 
mnnas  that  contractions  and  extensions  continued  after  the  flagella 
were  detached  from  the  body.  Biitschli  (1885)  describes  movements 


446  University  of  California  Publications  in  Zoology       [VOL.  19 

of  a  detached  flagellum  of  Glenodinium  cinctum,  which  rolled  up  in 
corkscrew  fashion,  remained  quiet  for  a  moment,  then  straightened 
out  and  soon  turned  over  in  an  up-and-down  movement.  These 
movements  lasted  for  only  a  minute  or  less,  after  which  the  detached 
flagellum  came  to  rest  and  did  not  move  again.  Schilling  (1891) 
observed  similar  reactions  in  detached  flagella  of  Peridinium  and 
Fischer  (1894)  saw  that  the  detached  flagellum  of  Polytoma  continued 
its  movements  for  some  time  after  it  had  separated  from  the  body. 
In  an  isolated  cilium  of  Phycomyceten  zoospores,  Rothert  (1894) 
clearly  observed  several  movements.  Kb'lsch  (1902)  saw  cilia  on  a 
blister  of  paramecium  that  continued  to  beat  rapidly.  He  thought 
that  to  these  cilia  the  basal  corpuscles  remained  attached.  In  detached 
cirri  of  Euplotes  harpa,  Prowazek  (1900)  observed  repeated  move- 
ments. 

It  is  not  uncommon,  during  the  disintegration  of  the  body  of  E. 
patella,  to  see  frontal  or  marginal  cirri  continue  several  contractions 
upon  being  set  free.  Occasionally,  but  less  frequently,  I  have  dis- 
tinctly observed  detached  anal  cirri  to  show  similar  movements.  Some- 
times the  movements  of  detached  frontal  cirri,  even  after  being  gouged 
out  by  the  needle,  were  quite  vigorous,  and  continued  so  for  several 
seconds.  As  formerly  stated,  frontal  and  marginal  cirri  have  been 
snipped  off  with  a  V-shaped  needle.  In  very  few  cases  was  it  possible 
to  cut  these  cirri  off  and  carefuly  observe  any  reactions  of  the  excised 
parts.  However,  such  parts  were  never  seen  to  contract.  Their  failure 
to  show  any  movement  may  have  been  due  to  injury  which  resulted 
in  rapid  death.  Anyhow,  from  the  various  ways  in  which  the  cirri 
of  this  animal  are  used,  not  only  in  creeping  and  swimming  but  also 
in  attachment  to  objects,  which  in  several  instances  were  observed  to 
involve  distinct  flexures  (as  over  the  needle  or  about  pieces  of  debris) 
it  would  seem  that  contractility  inheres  throughout  the  cirrus. 

Furthermore,  rather  more  frequently,  the  movements  of  the  mem- 
branelles  may  be  distinctly  seen  to  continue  after  separation  from  a 
disintegrating  body,  even  for  longer  periods  than  those  of  detached 
cirri.  As  few  as  four  membranelles  have  been  cut  off  which  after- 
wards showed  several  fairly  normal  movements.  Attempts  to  excise 
a  single  membranelle  and  observe  any  contractions  were  unsuccessful, 
but  the  failure  would  appear  to  be  due  rather  to  inferior  technique. 

It  is  obvious  that  the  contractions  of  anal,  frontal  or  marginal  cirri 
or  of  membranelles  of  E.  patella  are  not  conditional  upon  attachment 
to  the  body  and,  therefore,  not  upon  any  mechanism  within  the  body. 


Taylor:  Jfevromot or  Apparatus  in  Kujilotis  -147 

Another  matter  of  considerable  importance  here  concerns  any 
specific  t'unetion  which  a  group  of  organelles  in  E.  patella  may  per- 
form. Are  there  indications  of  a  division  of  labor  among  the  several 
groups  of  cirri  and  membranelles?  Since  in  many  ciliates  the  body 
is  definitely  differentiated  and  frequently  bears  several  sorts  of 
organelles.  such  as  cilia,  cirri,  membranelles,  etc.,  some  authors  have 
regarded  this  differentiation  in  the  form  and  position  of  organelles 
as  representing  a  division  of  labor  among  the  several  groups.  Pearl 
(1900)  concluded  from  observations  on  Colpidiiuti  that  th.-  effective 
stroke  of  a  group  of  anterior  cilia,  which  is  always  toward  the  oral 
side  when  the  animal  is  stimulated  by  the  electric  current,  caused  the 
body  to  turn  toward  the  aboral  side.  Similarly,  Putter  (1900)  observed 
that  the  peristomial  cilia  in  Stylonychia,  with  their  effective  stroke 
toward  the  oral  side,  produced  the  swerving  of  the  body  toward  the 
aboral  side. 

If  these  usual  movements  are  effected  wholly  by  a  special  group  of 
organelles,  then  the  movements  should  disappear  upon  the  removal 
of  those  structures.  Accordingly,  Jennings  and  Jamieson  (1902) 
undertook  to  ascertain  the  effect  of  the  removal  of  one  or  more  groups 
of  organelles  in  Stylonychia,  Stentor,  Spirostomum,  and  Paramoecium. 
These  investigators  found  that  when  any  of  these  ciliates  were  cut  into 
pieces,  "if  they  are  not  too  minute  or  too  irregular  in  form,  the  pieces 
swim  in  a  spiral,  swerving  continually  toward  a  certain  side,  just  as 
do  the  entire  organisms"  (p.  232).  It  became  evident,  therefore,  that 
the  usual  reactions  of  these  animals  could  not  be  attributed  to  any 
particular  set  of  structures,  but  that  all  the  organelles  have  a  share  in 
the  production  of  these  characteristic  movements. 

The  several  transections  made  on  E.  patella  indicated  a  similar 
tendency  in  the  movements  of  each  of  the  two  pieces.  Here,  however, 
the  reactions  were  not  so  definite  or  so  invariable  as  were  those  for 
ciliates  described  by  Jennings  and  Jamieson  (1902) .  It  will  be  recalled 
that  the  swimming  movements  of  E.  patella  are  more  varied  than  are 
those  described  for  the  above  animals.  In  addition  to  the  spiral 
swimming  movement  which  is,  indeed,  very  common  in  this  ciliate,  at 
least  five  other  characteristic  swimming  movements  have  been  identi- 
fied, three  of  which — the  circus  movement  to  the  right,  a  sharp  turn 
to  the  right,  and  the  backward,  avoiding  reaction — are  by  no  means 
uncommon.  Furthermore,  the  transections  have  shown  that  the 
anterior  piece  possessing  only  the  group  of  three  frontal  cirri  and 
adoral  membranelles  swam  almost  constantly  in  circuits  to  the  right, 


448  University  of  California  Publications  in  Zoology       [VOL.  19 

although  the  piece  reverted  occasionally  to  the  spiral  movement  and 
to  the  backward,  avoiding  reaction.  Now,  since  the  excised  oral  lip 
reacts  only  in  right  circus  movements,  it  would  appear  evident  that 
these  organelles  are  chiefly  responsible  for  the  same  movements  when 
only  the  three  frontal  cirri  are  added.  And  one  may  enquire  whether 
the  circus  movements  to  the  right  by  the  normal  animal  may  not  be 
effected  mainly  by  these  adoral  membranelles.  The  fact  that  when 
such  movements  are  performed  the  anal  and  marginal  cirri  not  in- 
frequently remain  wholly  passive,  and  that  these  movements  are  more 
common  after  the  anal  and  marginal  cirri  have  been  removed,  would 
lend  support  to  such  a  conclusion. 

It  was  also  observed  that  a  sharp  turn  to  the  right  was  accompanied, 
if  not  mainly  produced,  by  the  quick  lateral  flexure  of  the  anal  cirri, 
and  that  when  these  cirri  were  removed,  this  reaction  was  never  dis- 
tinctly observed. 

Again,  the  usual  reaction  of  the  posterior  part  resulting  from  a 
transection  just  anterior  to  the  anal  cirri,  was  a  rotation  with  the  cut 
surface  as  an  axis.  Circus  movemens  to  the  right  were  infrequent 
and  still  less  frequent  were  the  spiral,  revolving  movements  on  the 
long  axis.  In  fact,  neither  of  these  two  movements  was  seen  if  the 
marginal  cirri  had  been  snipped  off  previous  to  the  transections. 

From  these  observations,  therefore,  it  appears  that  in  E.  patella 
one  of  the  several  swimming  movements  prevails  in  a  piece  formed  by 
a  transection,  or  that  one  of  these  movements  becomes  less  frequent 
and  may  not  appear  at  all  upon  the  removal  of  a  group  of  organelles. 
such  as  the  anal  cirri. 

These  facts,  nevertheless,  are  not  contradictory  to  the  more  general  _ 
truth,  viz.,  that  all  the  locomotor  organelles  cooperate  in  the  per- 
formance of  any  characteristic  movement.  The  very  significance  of 
organization  precludes  any  other  interpretation.  But  are  we  to  regard 
each  group  of  organelles  equally  effective  in  producing  any  one  of 
these  movements  ?  If  so,  then  the  removal  of  the  marginal  cirri  should 
impair  a  given  movement  in  the  same  manner  and  to  the  same  extent 
as  excision  of  the  adoral  membranelles  impairs  that  movement.  But 
it  can  be  said  with  certainty  that  the  same  results  in  each  case  do  not 
follow.  Were  we  to  assume  that  all  the  locomotor  organelles  of  E. 
patella  function  to  the  same  end  with  equal  effectiveness,  it  would  be 
necessary  to  regard  both  the  adoral  membranelles  and  the  marginal 
cirri  as  distinctly  creeping  organs,  which  they  are  not.  In  this  respect, 
therefore,  we  may  speak  of  a  division  of  labor  among  the  locomotor 
organs  of  E.  patella. 


Tni/li'i-:   Newromotor  Apparatus  in  l-'.ni>l<>ttx  44it 


None  \vtmM  question  tlic  evidence  for  a  division  of  lalior  among  the 
intracytoplasmie  organelles  in  tins  ciliate.  and  the  several  experiments 
previously  deserilied  would  indicate  that  the  extraeytoplasmir  organ- 
elles.  also,  may  share  a  decree  of  speeilie.  but  none  the  less  coordinated, 
functions  in  the  animal's  normal  behavior.  Accordingly,  in  accom- 
plishing such  swimming  nioveinents  as  the  sharp  turn  to  the  right  or 
the  (|iiick  backward,  avoiding  reaction,  we  may  regard  the  anal  cirri 
as  especially  etl'ective  if  not  normally  indispensable,  much  as  the  large 
caudal  cirri  in  I'rcnii/cliin-  arc  largely  responsible  for  that  animal's 
very  rapid,  backward  movements  (Calkins.  11)11.  p.  l1^ 

In  this  consideration,  it  is  important  to  note  that  the  feature  of 
coordinated  activity  is  in  all  respects  evident  in  the  normal  K.  /xitilln. 
The  claim  here  made  is  that  the  perfection  of  both  creeping  and  swim- 
ming movements  is  dependent  upon  the  cooperation  particularly  of 
those  organdies  (e.g..  the  frontal  and  anal  cirri  in  creeping)  which 
contribute  most  effectively  to  the  performance  of  any  usual  movement. 
Therefore,  the  elimination  of  any  important  group  of  organelles,  or 
the  interference  with  any  mechanism  by  which  they  operate  or 
cooperate  with  another  similarly  important  group,  should  result  in 
perceptible  changes  in  swimming  or  in  creeping  movements. 

We  may  now  enquire:  Does  the  fibrillar  system  in  Eui>1otes  patella 
re])  resent  a  mechanism  that  affects  the  external  organelles  individually? 
Or  does  this  complex,  unified  apparatus  function  in  the  coordination 
of  all  the  several  groups  of  organelles  with  which  it  is  intimately 
associated?  An  affirmative  reply  to  the  first  question  would  assign 
either  a  supporting  or  a  contractile  function  to  this  system,  and  to 
affirm  the  second  question  is  to  attribute  to  the  system  the  function  of 
conductivity. 

The  experimental  evidences  set  forth  in  previous  paragraphs  sup- 
port an  affirmative  answer  to  the  second  question,  viz.,  that  this  fibrillar 
apparatus  exhibits  features  of  conductivity  functioning  to  coordinate 
the  groups  of  external  organelles  with  which  its  unified  and  dissociated 
parts  are  directly  or  indirectly  intimately  associated.  These  evidences, 
furthermore,  do  not  support  the  assumption  that  the  system  is  either 
contractile  or  supporting  in  function. 

The  facts  which  concern  these  three  propositions  may  be  stated  as 
follows  : 

Tin  fibrillar  system  in  E.  patella  is  not  skeletal  or  supporting  in 
function.  —  The  rigid,  fairly  tough  pellicle  is  amply  sufficient  to  main- 
tain the  normal  shape  of  the  body  under  considerable  stress.  It  was 


450  University  of  California  Publications  in  Zoology       [VoL- 19 

shown  that  the  pressure  of  a  very  flexible  needle  when  applied  to  the 
full  width  of  the  body  did  not  alter  the  normal  shape  of  the  animal. 
Also,  when  the  body  was  flattened  for  a  few  minutes  by  applying  a 
stiffer  needle,  or  by  surface  tension,  upon  releasing  the  stress  the  body 
at  once  recovered.  It  was  also  stated  that  the  pellicle  was  sufficiently 
tough  to  require  in  dissections  the  use  of  needles  with  fairly  stiff,  sharp 
points.  Other  needles  were  ineffective.  Furthermore,  the  firmness  of 
the  pellicle  is  sufficient  to  preserve  the  normal  shape  of  the  body  after 
an  incision  fully  two-thirds  its  width  had  been  made.  The  friction  of 
water,  induced  by  the  animal's  continuous  and  devious  swimming 
movements,  effected  no  visible  change  in  its  shape.  Any  momentary 
modification  in  the  shape  of  E.  patella  can  result  only  from  extraneous 
pressure.  Unlike  Paramoecium,  which  readily  forces  its  way  through 
narrow  meshes  of  silk  fibers  with  distinct  constrictions  of  the  body,  this 
animal,  owing  to  the  consistency  of  its  pellicle,  is  of  itself  unable  to 
alter  its  form. 

The  basal  plate  and  not  the  fiber  plate  is  the  means  of  secure 
attachment  and  support  for  both  the  cirri  and  the  membranelles.  The 
rootlets  of  the  component  cilia  of  both  membranelles  and  cirri  are 
imbedded  in  the  gelatinous  ectoplasmic  basal  plate  and  are  only  con- 
tiguous with,  but  not  attached  to,  the  fiber  plate.  The  readiness  with 
which  the  basal  plate  becomes  detached  from  the  fiber  plate  and  the 
want  of  any  indications  that  the  ciliary  rootlets  had  been  attached  to 
the  smooth,  clean  fiber  plate,  was  previously  described. 

The  consistency,  solubility,  size,  and  shape  of  the  fibers  are  incom- 
patible with  efficient  structures  for  support.  Particularly  are  the 
anal  cirri  fibers  frail,  readily  flexible,  and  irresilient.  They  may  be 
pulled  in  two  or  bent  variously  with  the  needle-point.  When  entirely 
free  from  the  ectoplasm  they  are  not  resilient  and,  by  means  of  the 
needle,  they  may  be  readily  distorted.  They  may  adhere  to  the  needle 
and  thus  be  pulled  about  through  the  water.  Their  dissolution  is 
sometimes  rapid  and  usually  occurs  within  fifteen  minutes  or  less 
after  being  exposed  to  the  water.  It  is  probable  that  they  are  not 
imbedded  in  the  ectoplasm  but  lie  upon  its  inner  surface,  being  sup- 
ported there  by  a  thin,  hyaloplasmic  sheath.  This  loose  attachment, 
together  with  the  extensive  length  and  the  minuteness  of  these  fibers, 
indicate  that  they  do  not  function  as  supporting  structures  either  for 
the  pellicle,  which  is  of  itself  distinctly  firm  and  resistant,  or  for  the 
cirri,  whose  component  cilia  are  not  attached  to,  but  only  contiguous 
with,  the  basal  plate. 


1920]  Taylor:  Neuromotor  App<inilita  in  Kui>lnlcx  451 

This  fibrillar  si/stim  is  not  cnntrartili:  in  fit  net  inn. — The  contrac- 
tility either  of  cirri  or  of  membranelles  is  not  conditioned  upon  their 
attachment  to  the  body  and  consequently  not  upon  any  mechanism 
within  the  body.  All  the  frontal,  ventral  marginal  and  anal  cirri  and 
inembranelles  have  distinctly  been  observed  to  continue  contractions 
for  a  considerable  period  after  their  detachment  from  the  body.  These 
reactions  have  already  been  discussed  somewhat  at  length,  and  need 
not  be  further  elucidated  here.  It  is  now  only  worth  while  to  empha- 
size that  their  capacity  of  contraction  inheres  within  these  external 
organelles  themselves.  Whether  this  contractility  is  effected  by  the 
basal  corpuscles,  the  axial  filament  of  the  component  cilia,  or  the 
plasmic  sheath  enclosing  the  filaments,  is  not  for  our  consideration. 

The  loose  attachment  of  the  basal  plate  to  the  fiber  plate  indicates 
that  the  fibrillar  system  differs  both  in  structure  and  in  function  from 
the  contractile,  external  organelles.  The  ease  and  completeness  with 
which  the  basal  plates  become  detached  from  the  fiber  plates  and  the 
want  of  evidence  that  the  ciliary  rootlets  and  fiber  plate  are  more 
than  merely  contiguous  structures  are  significant  features  supporting 
this  conclusion. 

The  consistency  of  the  anal  cirri  fibers  and  their  feeble  attachment 
to  the  ectoplasm  and  to  the  easily  displaced  motorium  would  suggest 
their  meager  effectiveness  in  functioning  as  contractile  structures. 
The  fibers  tend  to  remain  straight  when  undisturbed.  They  do  not 
become  kinked  or  curled  upon  the  disintegration  of  the  ectoplasm.  It 
is  only  by  means  of  the  needle  or  some  other  external  agency  that  they 
may  readily  become  distorted.  They  may  be  pulled  in  two  with  the 
needle-point  but  at  no  time  have  they  shown  any  indications  of 
stretching. 

The  reversibly  effective  strokes  of  the  anal  cirri  preclude  the  possi- 
bility that  the  anal  cirri  fibers  are  contractile  in  function.  The  four 
effective  strokes  of  these  cirri  have  been  described  in  foregoing  para- 
graphs. These  are:  (1)  directly  backward  strokes  parallel  to  the 
sagittal  plane,  (2)  directly  forward  strokes  parallel  to  that  plane, 
(3)  laterally  backward  strokes  hardly  parallel  to  the  frontal  plane, 
and  (4)  similar  lateral  strokes  directed  forward.  All  these  strokes 
have  been  seen  many  times  in  the  anal  cirri  of  a  transected  posterior 
piece  as  well  as  after  an  incision  which  had  clearly  severed  the  anal 
cirri  fibers.  Since  contractile  fibers  can  operate  effectively  only  in 
one  direction,  it  is  inconceivable  that  an  anal  cirri  fiber  can  function 
as  a  contractile  organelle. 


452  University  of  California  Publications  in  Zoology       [VOL.  19 

The  fibrillar  system  in  Euplotes  patella  does  possess  properties  of 
conductivity  functioning  to  coordinate  the  movements  of  the  external 
organelles  with  which  it  is  associated. — Normal,  coordinated  activity  of 
the  series  of  membranelles  is  effected  through  the  motorium,  the  mem- 
branelle  fiber  and  its  attached  inrmbninelle  plates.  An  incision  at  any 
point  through  the  oral  lip,  which  did  not  sever  the  membranelle  fiber, 
gave  negative  results.  But  when  the  membranelle  fiber  was  severed, 
there  were  conspicuous  changes  in  rhythmic  movements  of  the  mem- 
branelles on  either  side  of  the  incision  and  distinct  modifications  in 
the  animal's  swimming  movements.  It  was  stated  that  the  mem- 
branelles on  the  right  side,  whose  fiber  remained  connected  with  the 
motorium,  at  times  became  inactive  and  projected  straight  out  from 
their  base ;  only  occasionally  were  they  seen  to  move  in  apparent 
coordination  with  those  on  the  left  side  of  the  incision.  The  latter, 
the  fiber  of  which  had  lost  its  connection  with  the  motorium,  showed 
continuous  movements  with  their  effective  stroke  mostly  such  as 
normally  tends  to  drive  the  animal  forward.  This  tendency  in  the 
rate  of  movement  and  in  the  direction  of  the  effective  stroke  is  com- 
parable with  the  unchanging,  ceaseless  movements  of  the  adoral  mem- 
branelles of  the  excised  oral  lip  which  continually  moved  in  circuits 
to  the  right  and  was  never  observed  to  reverse  the  effective  stroke  of 
the  adoral  membranelles.  This  constancy  in  the  behavior  of  mem- 
branelles whose  fibrillar  connection  with  the  motorinm  is  severed  might 
suggest  that  their  usual  modifications  in  direction  of  stroke  and  rate 
of  movement  may  in  some  way  be  effected  through  the  motorium.  It 
is  furthermore  evident  that  the  unusual  swimming  movements  which 
followed  such  incisions  resulted  from  the  severing  of  the  membranelle 
fiber. 

Efficient,  coordinated  behavior  of  the  five  anal  cirri  is  effected 
through  the  normal  functioning  of  the  five  anal  cirri  fibers  with  their 
attached  fiber  plates.  The  effects  of  severing  these  fibers  at  any  one 
of  several  regions  (see  Incisions,  page  441,  above)  were  distinct  and 
more  or  less  constant.  The  infrequency  and  lack  of  facility  in  creep- 
ing which  was,  at  times,  obviously  initiated  by  the  frontal  cirri,  and 
the  rare  occurrence  of  the  avoiding  reaction  were  noteworthy  changes 
in  the  animal's  creeping  movements.  But  more  evident  were  its 
modifications  in  swimming.  There  was  a  marked  tendency  toward 
performing  circus  movements  to  the  right.  Sharp  turns  to  the  right 
were  infrequent  and  in  three  cases  at  no  time  observed.  The  rapid, 
backward,  avoiding  reaction  has  never  been  clearly  identified  after 


Tii'tliir:  If  euromotor  Apparatus  in  /•.'»/*/<//< \  \:\.\ 

the  anal  cirri  fibers  had  been  severed.  It  is  important  and  significant 
in  this  connection  to  recall  that  the  severing  of  the  anal  cirri  fibers 
did  not  incapacitate  any  of  the  four  movements  of  the  anal  cirri. 
Kadi  of  these  movenieiits  lias  been  clearly  observed  ill  the  anal  cirri 
upon  supporting  such  an  incised  animal,  ventral  side  down,  by  means 
of  a  very  flexible  needle  against  the  under  surface  of  the  cover-glass. 
Occasional,  usual  creeping  or  swimming  inovements  by  the  incised 
animal  might,  therefore,  be  expected  as  occurring  incidentally. 
A'-'-onlingly,  it  is  the  infrequency  of  these  occurrences  and  not  their 
absence  that  suggests  the  want  of  coordination  and  warrants  the  con- 
clusion that  the  fibers  are  conductive  in  function. 

Perfect  and  efficient  coordination  between  the  series  of  mcm- 
branelles  and  the  five  anal  cirri  is  accomplished  through  the  normal 
functioning  of  the  motorium  and  its  attached  fibers.  Whether  the 
fibers  were  cut  on  both  sides  of  the  motorium  or  the  motorium  dest  roved 
by  means  of  the  needle-point,  the  effects  were  very  much  the  same. 
The  usual  swimming  movements  were  more  distinctly  altered  than 
were  the  creeping  movements.  Changes  from  normal  conditions  were 
the  rarity  of  creeping  movements,  their  slow  rate,  very  infrequent 
avoiding  reactions  and  the  tendency  of  the  animal  when  not  swim- 
ming to  remain  quite  passive  on  debris  and  unusually  irresponsive  to 
mechanical  stimuli.  The  most  common  reactions  in  swimming  were 
the  right  circus  inovements.  which,  here,  were  more  often  combined 
with  abnormal,  spiral  revolutions  in  which  the  anterior  described  much 
wider  spirals  than  did  the  posterior  end.  In  no  case  was  the  backward 
swimming  reaction  observed,  although,  as  described  above,  the  reversal 
of  both  the  adoral  membranelles  and  the  anal  cirri  was  clearly  seen. 
It  will  be  recalled  that  when  the  anal  cirri  fibers  were  cut  very  con- 
spicuous effects  were  seen  in  the  want  of  concomitaney  and  coordina- 
tion between  the  movements  of  the  membranelles  and  of  the  anal  cirri. 
This,  perhaps,  showed  more  clearly  than  any  other  experimental 
evidences  that  this  fibrillar  complex  is  coordinative  in  function. 

1'ert'ect  and  efficient  coordination  between  the  series  of  mem- 
branelles and  anal  cirri  is  contingent  essentially  and  only  upon  the 
motorium  with  its  attached  fibrillar  complex.  Any  incisions  through 
any  region  of  the  body,  which  did  not  sever  or  injure  this  fibrillar 
apparatus  neither  impaired  the  perfect  coordination  of  the  mem- 
branelles and  anal  cirri,  nor  modified  the  animal's  normal  creeping 
and  swimming  movements.  Whether  these  incisions  did  or  did  not 
pass  through  the  macronucleus,  the  results  were  always  without 


454  University  of  California  Publications  in  Zoology       [VOL-  19 

noteworthy  consequences.  It  is  apparent,  then,  that  the  destruction  of 
the  motorium  or  the  severing  of  some  or  all  of  its  attached  fibers  is 
alone  accountable  for  modifications  in  the  perfect  and  efficient  coordi- 
nation between  the  series  of  membranelles  and  the  anal  cirri.  We  may, 
therefore,  regard  these  normal,  morphological  relationships  as  con- 
ditioning the  animal's  usual  behavior  both  in  creeping  and  in 
swimming. 

Previous  to  the  researches  of  Sharp  (1914)  and  Yocom  (1918), 
several  other  investigators  had  found  fibers  in  certain  ciliates,  which 
they  believed  to  represent  nervous,  elements.  Engelmann  (1880) 
described  distinct  fibers  associated  with  the  peripheral  and  anal  cirri 
of  Stylonychia  and  concluded  that  they  were  nervous  in  function. 
Neresheimer  (1903)  found  two  separate  fibrillar  systems  in  Stentor 
coeruleus,  one  of  which  possessed  muscular  and  the  other  nervous 
properties.  Their  shape,  size,  selective  staining,  and  relative  positions 
suggested  these  distinct  functions.  Moreover,  this  author  found  experi- 
mental evidence  supporting  his  interpretations.  Lebedew  (1908) 
describes  two  systems  of  fibrils  in  Trachelocerca  phoenicopterus.  On 
one  side  and  running  parallel  to  each  row  of  basal  corpuscles  appeared 
a  smooth,  structureless  fiber  staining  light,  while  another  larger,  less 
even  and  densely  staining  fiber  also  ran  parallel  to  the  row  of  corpuscles 
but  on  the  opposite  side.  The  latter  was  believed  to  be  a  myoneme  and 
the  former  was  perhaps  of  nervous  function. 

Other  authors  (Butschli,  1889;  Schuberg,  1891;  Schroder,  1906; 
Maier,  1903;  Prowazek,  1903;  Griffin,  1910)  have  discredited  the 
"nerve  hypothesis"  for  protozoans  and  have  attributed  to  such  systems 
of  fibers  either  the  function  of  support  or  of  contractility. 

It  would  seem  that  these  discordant  interpretations  may  owe  their 
origin  largely  to  differences  in  the  more  general  conception  of  the 
nature  of  organization  and  degree  of  specialization  among  the 
Protozoa.  And  it  is  in  the  forming  of  this  general  conception  that  the 
qualifying  attributes — unicellular,  primitive,  and  simple — assert  them- 
selves. In  the  light  of  the  complex,  embryogenic  processes  that  give 
rise  to  skeletal,  muscular  and  neural  tissues  in  the  many-celled  animals, 
it  is  not  easily  conceivable  how  a  single,  undivided,  simple  and  primi- 
tive "cell" — the  protozoan — could  evolve  organs  performing  these 
specialized  functions.  Furthermore,  it  is  evident  that  many  protozoans 
are  similar  in  general  appearance  and  in  method  of  division  to  a 
single  metazoan  cell;  both  are  defined  as  "a  mass  of  protoplasm  con- 
taining nuclear  substance  (chromatin)  concentrated  into  one  or  more 


Tiii//nr:  Neuromotor  Apparattu  in  l\uj>/otes  455 

nuclei"  (Mim-hiii.  1912.  p.  1).  Metazoan  organs  arc  composed  of  many 
cells  which  liavc  become  modified  and  often  highly  specialized  to  form 
tissues,  of  which  several  kinds  may  appear  in  the  same  organ.  On 
the  other  hand,  organs  of  the  Protozoa  are  not  composed  of  cells  but 
are  modifications  of  a  single  cell.  We  might,  therefore,  regard  the 
protoplasm  within  the  organs  of  the  protozoan  as  having  the  same 
general  physiological  properties  as  the  protoplasm  throughout  the 
protozoan  body  and  these  general  properties  should  be  possessed  in 
common  with  those  of  any  protoplasm  wherever  found. 

Now  one  general  property  of  all  protoplasm  is  the  propagation 
throughout  all  its  substance  of  an  excitation  effected  by  a  stimulus. 
The  morphological  continuity  of  this  substance  into  all  the  parts  or 
organs  of  the  protozoan  body  would  appear  to  be  the  only  essential 
condition  for  the  conduction  of  an  excitation,  wherever  initiated,  to 
any  such  part  or  organ.  If  this  condition  is  evident  in  all  protozoans, 
it  would  seem  that  specialized,  conductive  -structures  for  the  trans- 
mission of  excitations  were  unessential  and  useless.  Accordingly, 
caution  in  ascribing  a  nervous  function  to  a  structure  or  a  system  of 
structures  in  a  protozoan  body  is  justifiable. 

However,  may  not  as  much  be  said  for  other  general  properties  of 
protoplasm?  Chambers  (1917a)  has  shown  that  the  surface  layer  of 
marine  eggs  may  be  pulled  out  into  long  strands  "without  otherwise 
disturbing  the  contour  of  the  cell.  On  being  released  the  strands  tend 
to  curl  and  retract  slowly  until  they  disappear"  (p.  6).  Similar 
phenomena  may  be  readily  demonstrated  in  the  endoplasmic  globules 
of  E.  patella  that  frequently  form  with  the  escape  of  the  endoplasm 
into  the  water.  Also,  the  proverbial  amoeba  and  many  of  its  relatives 
display  the  phenomenon  of  contractility  in  normal  behavior,  as  do  also 
all  amoeboid  cells  of  the  Metazoa.  And  the  cytoplasm  of  amoebae 
possesses  no  fibrils  or  other  specialized  structures,  so  far  as  is  known. 
by  which  it  effects  contraction.  Nevertheless,  this  general  property  of 
the  cytoplasm  is  not  functioned  by  such  simple  and  primitive  means 
in  many  protozoans.  It  is  a  well-established  fact  that  in  the  so-called 
higher  forms  contractility  is  effected  mainly,  though  perhaps  not 
exclusively,  by  specialized  structures,  the  myonemes. 

If,  therefore,  in  the  "unicellular"  protozoan  the  general  property 
of  contractility  has  become  more  or  less  localized  in  special  organelles, 
what  should  restrain  conductive  protoplasm  from  the  specialization 
of  structures  to  facilitate  conductivity?  The  extreme  rapidity  with 
which  many  protozoans  react  to  stimuli  suggests  the  presence  of 


456  University  of  California  l'n  Mirations  in  Zoology       [VOL.  19 

specialized,  conducting  elements  in  their  protoplasm.  That  such  ele- 
ments in  the  ciliate,  Euplotes  patella.,  have  become  unified  into  an 
efficient,  integrated  system  for  the  coordination  of  its  associated 
oganelles.  is  supported,  it  is  believed,  by  experimental  evidences  set 
forth  in  foregoing  paragraphs. 

Should  further  experimentation  substantiate  these  results,  then 
their  significance  is  clear.  The  most  salient  feature  of  stmelures  and 
functions  in  the  Protozoa  as  in  the  Metazoa  is  not  cellularity  but 
organization.  The  external  organelles  of  a  protozoan  body  are  not 
mere  continuations  of  the  protoplasm  as  the  fingers  are  a  part  of  the 
glove.  They  are  rather  modifications  which  are  sometimes  distinctly 
specialized,  as  the  cirri  and  membranelles  of  E.  patella  clearly  indi- 
cate. Moreover,  the  complex,  integrated  fibrillar  apparatus  of  this 
organism  signifies  higher  specialization  in  its  intracytoplasmic  struc- 
tures. From  these  considerations  it  would  follow  that  any  general 
conception  of  the  Protozoa  which  assumes  that  any  and  all  of  this 
extensive  and  diversified  group  of  organisms  are  so  simple  and  primi- 
tive as  to  lack  specific  organization — the  specialization  of  intra-  and 
extracytoplasmic  organelles — is  inadequate  and  will  assuredly  be 
abandoned. 


SUMMARY 

The  fibrillar  system  in  Euplotes  patella,  found  and  described  by 
Yocom  (1918)  as  a  "neuromotor  apparatus,"  has  been  identified  in 
the  living  organism  both  with  and  without  the  aid  of  vital  dyes. 

Other  structures  of  this  system  not  previously  described  are : 
(a)  membranelle  fiber  plates,  each  of  which  is  contiguous  with  a  mem- 
branelle  basal  plate  and  is  attached  at  one  end  to  the  membranelle  fiber ; 
(&)  dissociated  fiber  plates  contiguous  with  the  basal  plates  of  the 
frontal,  ventral  and  marginal  cirri,  to  each  of  which  are  attached  the 
"dissociated  fibers." 

The  rectangular  anal  fiber  plates,  a  modification  of  the  posterior 
ends  of  the  anal  fibers,  directly  approximate  the  basal  plates  of  the 
anal  cirri. 

The  fairly  rigid  pellicle  is  amply  sufficient  to  maintain  the  normal 
shape  of  Euplotes  under  considerable  stress  and  after  an  incision  fully 
two-thirds  the  width  of  the  bodv  has  been  made. 


1920]  T<ii/lur:    .\  <  iirntniitur  . I  /i/nirnl us  in   Kiijtlotix  l-n 

The  ctint  ractility  of  cirri  or  of  memhranelles  is  not  contingent 
upon  their  attachment  to  the  body  and  consequently  not  upon  any 
mechanism  within  the  body. 

The  normal  locomotion  of  Kuplolix  /ml/lln  includes  three  creeping 
iiiovcincnts:  il)  straight  ahead.  'LM  a  quick  backward  movement, 
a  turn  to  the  right  laborally);  and  six  swimming  movements: 
(1)  forward  without  spiral  revolutions,  (2)  forward  in  spiral  revolu- 
tions. (3)  circus  movement  to  the  right,  (4)  circus  movement  to  the 
left  i  orally  i.  (5)  a  sharp  turn  to  the  right,  (6)  rapidly  backwards 
without  revolutions. 

It  was  evident  from  transections  of  the  body  and  excision  of  parts 
that  the  frontal  cirri  or  anal  cirri  arc  indispensable  to  normal  creeping 
movements,  that  the  adoral  membranelles  are  largely  responsible  for 
swimming  movement  •'!.  that  the  anal  cirri  function  chiefly  in  per- 
forming creeping  movement  2  and  swimming  movement  ~i.  and  that 
the  adoral  membranelles  and  anal  cirri  cooperate  to  effect  swimming 
movement  6. 

Cutting  the  membranelle'  fiber  results  in  conspicuous  differences  in 
the  behavior  of  the  adoral  membranelles  on  either  side  of  the  incision 
and  in  abnormal  spiral  revolutions  in  swimming. 

Severing  the  anal  cirri  fibers  affects  both  creepini,'  and  swimming. 
Creeping  movement  2  is  infrequent.  Swimming  movement  ">  was 
seldom  observed  and  (i  was  never  seen  after  the  fibers  had  been  severed. 

l>i  ^friii/hiii  lln  iiinliii-iiiiii  in-  ciillini/  //\  iiHnrlnil  flliii-ft  inli  rn/i>ts 
coordination  in  tin  iinin  nn  nix  of  tin  adoral  membranettes  am/  anal 
cirri. 

Any  incision  not  severing  either  the  membranelle  fiber  or  the  anal 
cirri  fibers  does  not  impair  normal  creeping  or  swimming  movements. 

These  experimental  evidences  do  not  support  the  assumption  that 
the  fibrillar  system  in  Kuplotes  patella  is  either  contractile  or  support- 
ing in  function,  but  they  indicate  that  this  complex  system  of  fibers 
does  possess  conductive  properties  functioning  in  the  coordination  of 
the  movements  of  the  locomotor  organelles  with  which  it  is  intimately 
associated. 


458  University  of  California  Publications  in  Zoology       [VOL-  19 


LITERATURE  CITED 

ALEXEIEFF,  A. 

1912.  Sur  la  revision  du  genre  Bodo  Ehrg.    Arch.  f.  Prot.,  26,  413-19,  1  fig. 

in  text. 

BARBER,  M.  A. 

1914.     The  pipette  method  in  the  isolation  of  single  microorganisms  and  in 
the  inoculation  of  substances  into  living  cells.     Philippine  Jour. 
Sci.,  9,  307-58,  19  figs,  in  text. 
BENDA,  C. 

1899.     Weitere   Mitteilung   tiber   die    Mitochondrion.      Arch.   f.    Anat.    und 
Physiol.  (Phys.  Abt.),  Jahrg.  1900,  166-78. 

BOECK,  W.  C. 

1917.  Mitosis  in  Giardia  microti.    Univ.  Calif.  Publ.  Zool.,  18,  1-26,  pi.  1. 

BRAUNE,  E. 

1913.  Untersuchungen  fiber  die  in  Wiederkauermagen  vorkommenden  Pro- 

tozoen.     Arch.  f.  Prot.  32,  5-63,  pis.  3-6. 

BUTSCHLI,  O. 

1885.     Einige  Bemerkungen  fiber  gewisse  Organisationsverhaltnisse  der  sog. 

Cilioflagellaten   und   der  Noctiluca.     Morphol.   Jahrb.,   10,   529-77, 

pis.  26-28,  4  figs,  in  text. 
1889.     Protozoa.     Bronn's  Klassen  und  Ordnungen  des  Thier-Eeichs.,  1  (3), 

1783-95. 

CALKINS,  G.  N. 

1911.     Eegeneration  and  cell  division  in   TJronychia.     Jour.  Exp.   Zool.,  10, 
95-116,  15  figs,  in  text. 

CHAMBERS,  R.,  JR. 

1914.  Some  physical  properties  of  the  cell  nucleus.     Science,  n.s.,  40,  824- 

827. 

1915.  Microdissection    studies    on    the    physical   properties    of   protoplasm. 

Lancet-clinic,  Cincinnati,  March  27. 
1917a.  Microdissection  studies.     I.  The  visible  structure  of  cell  protoplasm 

and  death  changes.     Amer.  Jour.  Physiol.,  43,  1-12,  2  figs,  in  text. 
19176.  Microdissection   studies.     II.   The   cell   aster:    a   reversible   gelation 

phenomenon:    Jour.  Exp.  Zool.,  23,  483-505,  pi.  1. 

1918.  The  microvivisection  method.    Biol.  Bull.,  34,  121-136,  8  figs,  in  text. 

DOBELL,    C.    C. 

1909.     Chromidia  and  the  binuclearity  hypothesis.     Quart.  Jour.  Micr.  Sci., 

53,  279-326,  25  figs,  in  text. 
DOFLEIN,  F. 

1911.     Lehrbuch  der  Protozoenkunde   (Jena,  Fischer),  ed.   3,  xii,  1043,  931 

figs,  in  text. 

ENGELMANN,  T.  W. 

1879.  Physiologie    der    Protoplasma-    und    Flimmerbewegung.      Hermann's 

Handbuch  der  Physiol.,  1,  341-408,  5  figs,  in  text. 

1880.  Zur  Anatomie  und  Physiologie  der  Flimmerzellen.     Pfliiger's  Arch.  f. 

d.  ges.  Phys.,  23,  505-535,  pi.  5. 


Tiii/lnr:   Newomot or  Apparatus  in  Kui>lul<x  459 

KKHARD,  H. 

1010.     Studion  iiber  Flimmerzellen.     Arch.  f.  Zellforseh.,  4,  310-427,  pis. 

L'l1.  -•:),  K>  figs,  iii  text. 

FlSCIIKR,    A. 

1894.     t)ber  ilif  (ii'isscln  einiger  Flagellaten.    Jahrb.  f.  vviss.  Botan.,  26,  187- 
886,  pis.  11,  1L'. 

GRIFFIN,  L.  E. 

1910«.  Kuplnti.1   u-ori'fittt  ri  sp.   nov.     I.   Structure.     Philippine   .Tour.    SIM.,   5, 

1'!' 1-31 2,  pis.  1-3,  13  figs,  in  text. 
1910ft.  Euploti.  i  ri  sp.  nov.    II.  Division.     Ibid.,  315-36,  pis.  4-8. 

GfRWITZ,    A. 

1904.     Morphologic  und  Biologic  der  Zelle  (Jena,  Fischer),  437  pp.,  239  figs. 
in  text. 

HENNEGUY,  L.  F. 

189'8.     Sur  le  rapports  des  cils  vihratiles  avec  les  centrosomes.    Arch.  d'Anat. 

Micr.,  1,  481-96,  10  figs,  in  text. 
JAXICKI.  ('. 

1915.     Untenadumgen    an    parasitischen    Flagellaten.      II.    Die    Gattuiijjrn 
Devescovina,   Parajoenia,    StepTianonymptia,    Calonympha.     Zeitschr. 
wiss.  Zool.,  112,  573-689,  pis.  13-18,  17  figs,  in  text. 
JENNINGS,  II.  S.,  AND  JAMIESON,  C. 

1902.  Studies   on   reactions   to   stimuli   in    unicellular   organisms.     X.    The 

movements  and  actions  of  pieces  of  oiliate  Infusoria.     Biol.  Bull., 
3,  225-34,  4  figs,  in  text. 
JOSEPH,    II. 

1903.  Beitriige  zur  Flimmerzellen-  und  Centrosomenfrage.     Arb.  a.  d.  Zool. 

Inst.  Tniv.  \Vien,  14,  1-81,  pis.  1-3,  3  figs,  in  text. 
KHAINSKT,  A. 

1910.     Zur   Morphologic   und   Physiologic   einiger   Infusorien    (Paramoecium 
caudatum)   auf  Grund  einer  neuen  histologischen  Methode.     Arch, 
f.  Prot.,  21,  1-60,  pis.  1-3,  2  figs,  in  text. 
KITE,  G.  L. 

1912.     The  nature  of  the  fertilization  membrane  of  the  egg  of  the  sea  urchin 

(Arbacia  putirtulata).    Science,  n.s.,  36,  562-64. 
1913<i.  The  relative  permeability  of  the  surface  and  interior  portions  of  the 

cytoplasm  of  animal  and  plant  cells.    Biol.  Bull.,  25,  1-7. 
19136.  Studies  on  the  physical  properties  of  protoplasm.  '  I.   The  physical 
properties  of  protoplasm  of  certain  animal  and  plant  cells.     Amer. 
Jour.  Physio!.,  32,  146-64. 

KITE,  G.  L.,  AND  CHAMBERS,  R.,  JB. 

1912.     Vital  staining  of  chromosomes  and  the  function  and  structure  of  the 

nucleus.     Science,  n.s.,  36,  639-41. 
KLEBS,  G. 

1881.     tJber  die  Organisation   einiger  Flagellatengruppen  und   ihre  Bezieh- 
ungen  zu  Algen  und  Infusorien.     Untersuch.  aus  d.  Botan.  Inst.  zu 
Tubingen,  1,  233-362,  pis.  2,  3. 
KOLACEV,  A. 

1910.     t)ber  den  Bau  des  Flimmerapparates.     Arch.  mikr.  Anat.,  76,  349-72, 
pi.  17,  2  figs,  in  text. 


460  University  of  California  Publications  in  /oology       [VOL.  19 

KOLSCH,  KARL. 

1902.  Untersuchungen  iiber  die  Zerfliessungserscheinungen   der  ciliaten  In- 

fusorien.     Zool.  Jahrb.  Abt.  f.  Anat.  u.  Ontog.,  16,  273-422,  pis.  26- 
28,  5  figs,  in  text. 

KOFOID,  C.  A.,  AND  CHRISTIANSEN',  E.  B. 

1915a.  On  Gianlin.  microti,  sp.  nov.,  from  the  meadow  mouse.     Univ.  Calif. 

Publ.  Zool.,  16,  23-29,  1  fig.  in  text. 
19156.  On  binary  and  multiple  fission  in  Giardia  muris  (Grassi).     Ibid.,  16, 

30-54,  pis.  5-8,  1  fig.  in  text. 

KOFOID,  C.  A.,  AND  SWEZY,  O. 

1915.     Mitosis  and  multiple  fission  in  triehomonad  flagellates.     Proc.  Amer. 

Acad.  Arts  and  Sci.  Boston,  51,  289-378,  pis.  1-8,  7  figs,  in  text. 
LEBEDEW,  W. 

1908.  Tiber  Trachelocerca  pjioenicopterus  Colin.  Ein  marines  Infusor.  Arch, 
f.  Prot.  13,  70-114,  pis.  7,  8,  7  figs,  in  text. 

LKNHOSSEK,  M.  v. 

1898.     uber  Flimmerzellen.    Verh.  d.  anat.  Ges. 

MAIER,  II.  N. 

1903.  Ueber  den  feineren  Bau  der  \Vimperapparate  der  Infusorien.     Arch. 

f.  Prot.,  2,  73-179,  pis.  3,  4. 

MARTIN,  C.  H. 

1913.  Further  observations  on  the  intestinal  Trypanoplasma  of  fishes.  Quart. 
Jour.  Micr.  Sci.,  59,  175-193,  pis.  9,  10,  2  figs,  in  text. 

MAUPAS,  E. 

1883.  Contribution  a  1  'etude  morphologique  et  anatomique  des  infusories 
cilies.  Arch.  Zool.  Exp.  et  Gen.,  (2),  1,  427-664,  pis.  19-24. 

MINCHIN,  E.  A. 

1912.  An  introduction  to  the  study  of  the  Protozoa  (London,  Arnold),  xi, 
520  pp.,  194  figs,  in  text. 

MINKIEWIEZ,  R. 

1901.  Studies  on  the  Protozoa  of  the  Black  Sea.  I.  The  organization,  multi- 
plication and  systematic  position  of  the  genus  Euplotes  Ehrbg. 
(In  Russian,  with  a  resume  in  French.)  Trudi  Kazan  Univ.,  35, 
1-67,  pis.  1,  2. 

MOBIUS,  K. 

1887.  tfber  die  Theilung  des  Euplotes  Jiarpa.  Sitzungsber.  d.  Ges.  nat. 
Freunde  Berlin,  1,  102-103. 

NERESHEIMER,  E.  R. 

1903.     Die   Hohe   histologischer   Differenzierung  bei   heterotrichen   Ciliaten. 

Arch.  f.  Prot.,  2,  305-24,  pi.  7,  1  fig.  in  text, 
PEARL,  R. 

1900.     Studies  on  electrotaxis.    I.  On  the  reactions  of  certain  Infusoria  to  the 

electric  current.     Amer.  Jour.  Physiol.,  4,  96-123,  7  figs,  in  text. 
PETER,  K. 

1899.  Das  Centrum  fur  die  Flimmer-  und  Geisselbewegung.  Anat.  Anz.,  15, 
271-283,  4  figs,  in  text. 

PRENANT,  A. 

1914.     Les  appareils  cilies  et  leurs  derives.    Jour.  d'Anat.  et  de  Physiol. 


Tai/lur:    .V<  un»ii"tnr  A />ininif  nx  in   Kitjilolt . t  4C1 

,    V/F.K,    S. 

llMKi.      I'nito/.o.mstudion,   III.   Kiiiilnttx  linri>,i.     Arb.  Zool.  lust.,   riii\.    \Vien, 

14,  Sl-SS,  ]»1.   1. 

1'i'TTF.R.    AUG. 

1900.  Studien   iibor  Thigimitaxis  bei  Protiston.     Arch.   f.   Anat.   u.   IMiysiol., 

I'liysiol.   Al.th.,  1900,  Supplementliuml,  ]«|>.  iM.'i-IHIl',  11    figs,  in  toxt. 
1903.     Die  Flininierbowr»mig.     Krgi-bn.  d.  I'hysiol.,  2,  1-1 0.,   1."   li^s.  in  text. 

ROTHERT.    \V. 

1894.      i  !,,  ,   ,|:ls  Sdiicksal  .lor  Cilien  bei  den  Zoiisporcn  Phyroinycoten.     Ber. 

dor  deutsch.  Botan.  Gesellsch.,  12,  L'I^  82,  pi.  1. 
SACITIII.  s. 

I'.UT.     Stuilios   on   ciliatf.1   colls,     .lour.   Morph.,  29,   '2\  7   i;i;s.   pis.   1-4,  1   fig. 
in  text. 

Sciin.uxii.  A.  3. 

1891.      Dio  SiisswasMT    I'ori.linccn.     Flora  oder  nllfjom.     Hot.  Zeituns.    Neue 

Koiho.  49,  L'^II-I;!)!!.  pis.  8-10. 
SCHROEDER,    O. 

-•>'•,.      Hi-itriijii*  ^ur  Kenntnis  von  Ktrntnr  roirulfiix  Khrlij;.  mid  Hlfiitnr  r<i<-si-Hi 
Ehrbg.     Arch.  f.  Prot.,  8,  1-16,  pi.  1,  1   njr.  in  text. 

Sc  III-BERG,    A. 

1891.     Zur  Konntnis  dcs  St,  nlnr  ooemfew.     Zool.  Jalirb..  4,  107-'J38,  pi.  14. 

SF.IFRIZ,  W. 

1918.     Observations  on  the  structure  of  protoplasm  by  aid  of  microdissee- 
tion.    Biol.  Bull.,  34,  307-24,  4  figs,  in  text. 

SHARP,  R.(i. 

1914.     Dijil, illinium  «'<iii<liilnm  with  an  account  of  its  neuromotor  apparatus. 
Univ.  Calif.  Publ.  Zool.,  13,  43-122,  pis.  3-7,  4  figs,  in  text. 

SlMROTH,   H. 

1876.     Zur   Kenntnis   des   Bewefjuntfsapparates   der   Infusionsthiere.      Arch. 

mikr.  Annt.,  12,  51-86,  pi.  9. 
STUART,  A. 

1867.     t'ber  die  Flimmerbewegung.     Inaug.-Diss.  Dorpat,  1-45. 

SWEZT,  O. 

1916.     The  kinetonucleus  of  flajrellates  and  the  binuclear  theory   of  Hart- 
mann.     TTniv.  Calif.  Publ.  Zool.,  16,  185-240,  58  figs,  in  text. 

WAUEXOREX,  H. 

1901.  Zur   Kenntnis   des   Neubildungs-    und    Resorptions-   Process   bei    der 

Theilung  der  hy]>otrichen  Infusorien.    Zool.  Jahrb.,  Abth.  f.  Anat., 

15,  1-58,  pi.  1,  28  figs,  in  text. 

WHITMORE.  E.  K. 

101  H).  Stuilien  iiber  Kulturamoeben  aus  Manila.     Arch.  f.  Prot.,  23,  81-93, 
]>ls.  3,  4. 

WU.SON-.  C.  W. 

1916.     On  the  life  history  of  a  soil  amoeba.     T'niv.  Calif.  Publ.  Zool. ,'18. 
241-92,  pis.  18-23. 

YOCOM,  H.  B. 

1918.     The  neuromotor  apparatus  of  Euplotes  patella.    Univ.  Calif.  Publ.  Zool., 
18,  337-396,  pis.  14-16,  1  fig.  in  text. 


EXPLANATION  OF  PLATES 

PLATE  29 

Fig.  1.  Transverse  incision  through  three-fourths  of  the  body,  after  which 
the  animal  maintained  normal  form.  X  800.  a.c.,  anal  cirrus;  a.c.f.,  anal  cirri 
fiber;  ant.  cyt.  f.,  and  nib.  f.,  membranelle  fiber;  c.v.,  contractile  vacuole;  cyt., 
cytostome;  f.c.,  frontal  cirri;  m.c.,  marginal  cirri;  mac.,  macronucleus;  m.f.p., 
membranelle  fiber  plate;  mic.,  micronucleus;  mot.,  motorium;  o.L,  oral  lip;  ph., 
pharynx. 

Fig.  2.  Transection  between  ' '  group  of  three ' '  and  ' '  group  of  four ' '  frontal 
cirri.  Dorsal  view.  X  800. 

Fig.  3.  Transection  between  "group  of  four"  frontal  cirri  and  the  two 
ventral  cirri.  X  800. 

Fig.  4.     Transection  between  the  two  ventral  cirri  and  five  anal  cirri. 


[462] 


UNIV.    CALIF.    PUBL.    ZOOL.    VOL.    19 


[TAYLOR  )    PLATE   29 


ant.  cyt.  f. 
\  -  •  mot. 


m.c. 


a.  c.  f. 


PLATE  30 

Fig.  5.  Incision  through  the  oral  lip  severing  the  membranelle  fiber.  X  800. 
ac.,  anal  cirrus;  a.c.f.,  anal  cirri  fiber;  ant.cyt,f.  and  mb.f.,  membranelle  fiber; 
c.v.,  contractile  vacuole;  f.e.,  frontal  cirri;  m.c.,  marginal  cirri;  mac.,  macro- 
nucleus;  m.f.p.,  membranelle  fiber  plate;  mic.,  micronucleus;  mot.,  motorium; 
o.l.,  oral  lip;  ph.,  pharynx. 

Fig.  6.  Incision  through  the  cytostomal  membraneles,  cutting  the  mem- 
branelle fiber.  X  800. 

Fig.  7.  Incision  cutting  the  anal  cirri  fibers  between  the  "group  of  three" 
and  "group  of  four"  frontal  cirri.  X  800. 

Fig.  8.  Incision  between  the  "group  of  four"  frontal  cirri  and  the  two 
ventral  cirri,  severing  the  anal  cirri  fibers.  X  800. 


[464] 


UNIV.    CALIF.    PUBL.    ZOOL.    VOL.    19 


[TAYLOR  ]    PLATE    30 


O.I -^ 


ant.  cyt.  f. 
-mot. 


a.c.f. 


----  -V.  C. 


m.c. 


PLATE  31 

Fig.  9.  Incision  anterior  ot  the  anal  cirri,  cutting  the  anal  cirri  fibers. 
X  800.  a.c.,  anal  cirrus;  a.c.f.,  anal  cirri  fiber;  ant.  cyt.  f.  and  mb.f.,  membranelle 
fiber;  c.v.,  contractile  vacuole;  f.c.,  frontal  cirri;  m.c.,  marginal  cirri;  mac., 
macronucleus;  m.f.p.,  membranelle  fiber  plate;  mic.,  micronucleus;  mot.,  motor- 
ium;  o.l.,  oral  lip;  ph.,  pharynx. 

Figs.  10,  11,  and  12.  Incisions  not  severing  the  anal  cirri  fibers  or  the  mem- 
branelle fiber. 


[466] 


UNIV.   CALIF.    PUBL.    ZOOL.    VOL.    19 


[TAYLOR]    PLATE   31 


O.I 


—  ant.  cyt.  f. 
--  mot. 


m.c. 


-a.c. 


c,v. 


10 


11 


12 


PLATE  32 

Fig.  13.  Diagram  of  the  neuromotor  apparatus.  X  1600.  a.c.f.,  anal  cirri 
fiber;  a.f.p.,  anal  fiber  plate;  m.f.,  membranelle  fiber;  m.f.p.,  membranelle  fiber 
plate;  mot.,  motorium. 

Pig.  14.  Anal  cirrus  detaching  from  its  fiber  plate.  The  cirris  has  rotated 
90  degrees  on  its  long  axis.  X  1450.  a.c.f.,  anal  cirri  fiber;  a.f.p.,  anal  fiber 
plate;  b.p.,  protoplasmic  basal  plate;  e.g.2,  large  ectoplasmic  granules;  n.p., 
needle  point. 

Fig.  15.  Anal  fiber  plate  with  a  portion  of  its  attached  fiber  distorted  by 
the  needle  point.  X  1450. 

Fig.  16.  Diagram  of  a  membranelle  showing  its  relation  to  the  membranelle 
plate.  X  1450.  b.g.,  basal  granule;  c.r.,  ciliary  rootlet;  f.p.,  fiber  plate. 

Fig.  17.  Dissected  portion  of  disintegrating  membranelle  fiber  plates  at- 
tached to  the  membranelle  fiber.  X1450.  mf.p.,  membranelle  fiber  plate; 
m.f.,  membranelle  fiber;  e.g.,,  large  ectoplasmic  granule;  e.g.ls  small  ectoplasmic 
granule. 


[468] 


UNIV.    CALIF.    PUBL.    ZOOL.    VOL.     19 


[TAYLOR  ]    PLATE    32 


L ,ac. 


15 


.e.g. 


PLATE  33 

Fig.   18.     Dorsal  view  of  anal  cirrus.     X  1450. 

Fig. -19.  Left  lateral  view  of  anal  cirrus.  X  1450.  a.c.,  anal  cirrus;  'b.g., 
basal  granule;  c.r.,  ciliary  rootlet;  p.gl.,  coagulated  protoplasmic  globule. 

Fig.  20.  Ventral  view  of  anal  cirri,  fibers  and  plates  lying  among  the  dis- 
integrating ectoplasm.  Anal  cirri  have  turned  90  degrees  on  their  long  axis. 
X  1450.  a.c.,  anal  cirrus;  a.c.f.,  anal  cirri  fiber  showing  portion  of  its  plate 
dorsal  to  the  cirrus;  e.g.^  and  e.g.,,  small  and  large  ectoplasmic  granules. 

Fig.  21.     Plates  and  fibers  of  five  frontal  cirri.     X  1430. 

Fig.  21a.  Dissociated  fiber  plates  of  the  ventral  cirri  with  their  attached 
fibers.  X  1450. 

Fig.  22.  Lateral  view  of  a  detached  menibranelle  previous  to  disintegration. 
X  625. 

Fig.  22a.  Disintegrating  menibranelle  showing  the  component  cilia  each 
with  its  basal  granule  and  ciliary  rootlet.  X  625.  &.#.,  basal  granule;  c.m., 
membranelle  cilium;  c.r.,  ciliary  rootlet;  p.gl.,  protoplasmic  globule. 

Fig.  23.  A  frontal  cirrus  attached  to  the  disintegrating  ectoplasm..  X  625. 
e.g.,  ectoplasmic  granule;  f.c.,  frontal  cirrus. 


[470] 


UNIV.   CALIF.    PUBL.    ZOOL.    VOL.    19 


[TAYLOR ]    PLATE   33 


-d.f. 


21  a 


22  a 


UNIVEBSITY  OF  CALIFORNIA  PUBLICATIONS — (Oontinuea) 

11.  A  Study  of  the  Races  of  the  White-Fronted  Goose  (Anser  albifrons)  occur- 

ring In  California,  by  H.  8.  Swarth  and  Harold  C.  Bryant.    Pp.  209  222, 

2  figures  In  text,  plate  13.    October,  1917  _      OB 

12.  A  Synopsis  of  the  Bats  of  California,  by  Hilda  Wood  OrinnelL  Pp.  223-404, 

plates  14-24,  24  text  figures.    January  31,  1918  _ _.    2.00 

13.  The  Pacific  Coast  Jays  of  the  Genus  Apheloi-oma,  by  H.  S.  Swarth.     Pp. 

405-422,  1  figure  in  t«xt.    February  23,  1918  .20 

14.  Six  New  Mammals  from  the  Mohave  Desert  and  Inyo  Regions  of  California, 

by  Joseph  Grinnell.    Pp.  423-430. 

15.  Notes  on  Some  Bats  from  Alaska  and  British  Columbia,  by  Hilda  Wood 

Grinnell.    Pp.  431-433. 

Nos.  14  and  15  In  one  cover.    April,  1918 .15 

16.  Eevlsion  of  the  Rodent  Genus  Aplodontia,  by  Walter  P.  Taylor.     Pp.  435- 

504,  plates  25-29,  16  text  figures.    May,  1918  _      .76 

17.  The  Subspecies  of  the  Mountain  Chickadee,  by  Joseph  Grinnell.    Pp.  SOS- 

SIS,  3  text  figures.    May,  1918  16 

18.  Excavations  of  Burrows  of  the  Rodent  Aplodontia,  with  Observations  on 

the  Habits  of  the  Animal,  by  Charles  Lewis  Camp.    Pp.  517-536,  6  figures 

in  text.    June,  1918  20 

Index,  pp.  537-545. 

Vol.  18.    1.  Mitosis  in  tiiimlia  microti,  by  William  C.  Boeck.     Pp.  1-26,  plate  1.    Octo- 
ber,  1917  36 

2.  An  Unnsual  Extension  of  the  Distribution  of  the  Shipwora  In  San  Fran- 

cisco Bay,  California,  by  Albert  L.  Barrows.    Pp.  27-43.    December,  1917.      .20 

3.  Description  of  Some  New  Species  of  Poli/noiilm-  from  the  Coast  of  Cali- 

fornia, by  Christine  Essenberg.    Pp.  45-60,  plates  23.    October,  1917 .20 

4.  New  Species  of  Ainplnnomifliie  from  the  Pacific  Coast,  by  Christine  Essen- 

berg.    Pp.  61-74,  plates  4-5.    October,  1917  __      .16 

6.  Critliiiliu  niriinplttftalmi.  sp.  nov.,  from  the  Hemipteran  Bug,  EvritophtlKilmus 
coni'iru*  Stal,  by  Irene  McCulloch.  Pp.  75-88,  35  text  figures.  Decem- 
ber, 1917  .15 

6.  On  the  Orientation  of  Erythropsis.  by  Charles  Atwood  Kofoid  and  Olive 

Swezy.  Pp.  89-102,  12  figures  in  text.    December,  1917 IB 

7.  The  Transmission  of  Nervous  Impulses  in  Relation  to  Locomotion  in  the 

Earthworm,  by  John  F.  Bovard.    Pp.  103-134,  14  figures  in  text.    January, 
1918    35 

8.  The  Function  of  the  Giant  Fibers  in  Earthworms,  by  John  F.  Bovard.    Pp. 

135-144,  1  figure  in  text.    January,  1918  _      .10 

9.  A  Rapid   Method  for  the  Detection   of   Protozoan   Cysts  in  Mammalian 

Faeces,  by  William  C.  Boeck.    Pp.  145-149.    December,  1917 08 

10.  The  Musculature  of  Heptanchits  maculatus,  by  Pirie  Davidson...  Pp.  151-170, 

12  figures  in  text.    March,  1918  _ 35 

11.  The  Factors  controlling  the  Distribution  of  the  Polynoldae  of  the  Pacific 

Coast  of  North  America,  by  Christine  Essenberg.    Pp.  171-238,  plates  6-8, 

2  figures  in  text.     March,  1918.... .76 

12.  Differentials  in  Behavior  of  the  Two  Generations  of  Salpa  democratica 

Relative  to  the  Temperature  of  the  Sea,  by  Ellis  L.  Michael.    Pp.  239-298, 
plates  9-11,  1  figure  in  text.    March,  1918 .88 

13.  A  Quantitative  Analysis  of  the  Molluscan  Fauna  of  San  Francisco  Bay,  by 

E.  L.  Packard.    Pp.  299-336,  plates  12-13,  6  figs,  in  text.    April,  1918 .40 

14.  The  Neuromotor  Apparatus  of  Euplotes  patella,  by  Harry  B.  Yocom.    Pp. 

337-396,  plates  14-16.    September,  1918  .70 

15.  The  Significance  of  Skeletal  Variations  in  the  Genus  Peridinium,  by  A.  L. 

Barrows.    Pp.  397-478,  plates  17-20,  19  figures  In  text.    June,  1918 90 

16.  The   Subclavian  Vein   and  its  Relations  in  Elasmobranch   Fishes,  by  J. 

Frank  Daniel.    Pp.  479-484,  2  figures  in  text.    August,  1918  — .10 

17.  The  Cercaria  of  the  Japanese  Blood  Fluke,   Srhisinsoma  japonicum  Kat- 

surada,  by  William  W.  Cort    Pp.  485-507,  3  figures  in  test. 

18.  Notes  on  the  Eggs  and  Miracidia  of  the  Human  Schlstosomes,  by  William 

W.  Cort.    Pp.  509-519,  7  figures  In  text. 

Nos.  17  and  18  in  one  cover.    January,  1919 _ .35 

Index  in  preparation. 


UNIVERSITY  OP  CALIFORNIA  PUBLICATIONS— (Continued) 

Vol.  19.  1.  Reaction  of  Various  Plankton  Animals  with  Reference  to  their  Diurnal 

Migrations,  by  Calvin  O.  Esterly.    Pp.  1-83.    April,  1919_ _ .86 

2.  The  Pteropod  Desmoptcrus  pacificus   (sp.  nov.),   by   Christine  Essenberg. 

Pp.  85-88,  2  figures  in  text.     May.   1919  05 

3.  Studies  on  Giardia  microti,  by  William  C.  Boeck.     Pp.  85-136,  plate  1,  19 

figures  in  text  60 

4.  A  Comparison  of  the  Life  Cycle  of  Crithidia  with  that  of  Trypanosoma  in 

the  Invertebrate  Host,  by  Irene  McCulloch.  Pp.  135-190,  plates  2-6,  3 
figures  in  text.  October,  1919  60 

5.  A  Muscid  Larva  of  the  San  Francisco  Bay  Region  •which  sucks  the  Blood 

of  Nestling  Birds,  by  O.  E.  Plath.  Pp.  191-200.    February,  1919  „      J.O 

6.  Binary  Fission  in  Collodictyon  triciliatum  Carter,  by  Robert  Clinton  Rhodes. 

Pp.  201-274,  plates  7-14,  4  figures  In  text.     December,  1919 1.00 

7.  Tie  Excretory  System  of  a  Stylet  Cercarla,  by  William  W.  Cort.    Pp.  275- 

281,  X  figure  in  text.    August,  1919  10 

8.  A  New  Distome  from  Sana  aurora,  by  William  W.  Cort.     Pp.  283-298, 

5  figures  in  text.     November,   1919 20 

9.  The  Occurrence  of  a  Rock-Boring  Isopod  along  the  Shore  of  San  Fran- 

cisco Bay,  California,  by  Albert  L.  Barrows.  Pp.  299-316,  plates  15-17. 
December,  1919 25 

10.  A  New  Morphological  Interpretation  of  the  Structure  of  Noctihica,  and 

its  Bearing  on  the  Status  of  the  Cystoflagellata  (Haeckel),  by  Charles 

A.  Kofoid.    Pp.  317-334,  plate  18,  2  figures  in  text.    February,  1920 25 

11.  The  Life  Cycle  of  Echinostoma  revolutum  (Froelich),  by  John  C.  Johnson. 

Pp.  338-388,  plates  19-25,  1  text  figure.     May,  1920  60 

12.  On  Some  new  Myriopods  Collected  in  India  in  1916  by  C.  A.  Kofoid,  by 

Ralph  V.  Chamberlin.     Pp.  389-402,  plates  26-28.    August,  1920 20 

13.  Demonstration  of  the  Function  of  the  Neurotnotor  Apparatus  in  Euplotes 

by  the  Method  of  Microdissection,  by  Charles  V.  Taylor.  Pp.  403-470, 
plates  29-33,  2  figures  in  text.  October,  1920 85 

Vol.20.  1.  Studies  on  the  Parasites  of  the  Termites.  I.  On  Streblomastix  strix,  a 
Polyinastigote  Flagellate  with  a  Linear  Plasmodial  Phase,  by  Charles 
Atwood  Kofoid  and  Olive  Swezy.  Pp.  1-20,  plates  1-2,  1  figure  in  text. 
July,  1919  .-. 25 

2.  Studies  on  the  Parasites  of  the  Termites.    II.    On  Trichamitus  termitidis, 

a  Polymastigote  Flagellate  with  a  Highly  Developed  Neuromotor  System, 
by  Charles  Atwood  Kofoid  and  Olive  Swezy.  Pp.  21-40,  plates  3-4,  2 
figures  in  text.  July,  1919 25 

3.  Studies  on  the  Parasites  of  the  Termites.  III.  On  TricJumympha  campanula 

Sp.  Nov.,  by  Charles  Atwood  Kofoid  and  Olive  Swezy.  Pp.  41-98,  plates 
5-12,  4  figures  in  text.  July,  1919  .75 

4.  Studies  on  the  Parasites  of  the  Termites.    IV.     On  Leidi/opsis  iphaerica 
gen.  nov.,  sp.  nov.,  by  Charles  Atwood  Kofoid   and   Olive   Swezy.     Pp. 
99-116,  plates  13-14,  1  figure  in  text.     July,  1919 „ 25 

5.  On  the  Morphology  and  Mitosis  of  Chilomastix  mesnili  (Wenyon),  a  Common 

Flagellate  of  the  Human  Intestine,  by  Charles  A.  Kofoid  and  Olive  Swezy. 

Pp.  117-144,  plates  15-17,  2  figures  in  text.    April,  1920 35 

6.  A  Critical  Review  of  the  Nomenclature  of  Human  Intestinal  Flagellates, 

Ce.rcomonas,  Chilomastix,  Trichomonas,  and  Giardia,  by  Charles  A.  Kofoid. 

Pp.  145-168,  9  figures  in  text.    June,  1920  35 

Vol.  21.  1.  A  Revision  of  the  Microtus  calif ornicus  Group  of  Meadow  Mice,  by  Rem- 
ington Kellogg.  Pp.  1-42,  1  figure  In  te-rt.  December,  1918 _ .50 

2.  Five  New  Five-toed  Kangaroo  Rats  from  California,  by  Joseph  Grinnell. 

Pp.  43-47.    March,  1919  05 

3.  Notes  on  the  Natural  History  of  the  Bushy-Tailed  Wood  Rats  of  California, 

by  Joseph  Dixon.    Pp.  49-74,  plates  1-3,  3  figures  in  text.    December,  1919      .25 

4.  Revision  of  the  Avian  Genus  Passerella,  with  Special  Reference  to  the  Dis- 

tribution and  Migration  of  the  Races  in  California,  by  H.  8.  Swarth. 

Pp.  75-224,  plates  4-7,  30  figures  in  text.    September,  1920  1.75 

5.  A  Study  of  the  California  Jumping  Mice  of  the  Genus  Zapus,  by  A.  Brazier 

Howell.    Pp.  225-238,  1  text  figure.    May,  1920 15 

Vol.  22.  1.  A  Quantitative  and  Statistical  Study  of  the  Plankton  of  the  San  Joaquin 
River  and  its  Tributaries  in  and  Near  Stockton,  California,  in  1913, 
by  Winfred  Emory  Allen.  Pp.  1-292,  plates  1-12,  1  text  figure.  June, 
1920 S.OO 


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